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--- Tagan SuperRock TG680-U33II 680 Watt Power Supply Unit (https://www.pc-experience.de/wbb2/thread.php?threadid=28167)

Geschrieben von Heaven am 30.11.2008 um 12:37:

Achtung Tagan SuperRock TG680-U33II 680 Watt Power Supply Unit

Tagan SuperRock TG680-U33II 680 Watt Power Supply Unit


As promised before, our little Tagan SuperRock roundup goes to the second round. After the TG5000-U33II with 500 Watt and Enhance layout, the TG680-U33II 680 Watt has to show its efficiency. Manufactured by Impervio and starting with a power output of 680 Watt, the SuperRock PSUs include the DC-to-DC technology for the first time. Not only Tagan hope to achieve a considerably higher stability concerning the current supply and a higher efficiency in using this technology. Of course there will be a separate chapter about this technology, which is not as new as maybe many people think.
With a power rating starting from 600 Watt, Tagan wants to provide PSUs for users who would like to overclock their systems and who are using Crossfire and SLI technology. It is interesting to see that the PSU market is already overflowed with PSUs of this power class. Apparently many manufacturers believe that most users overclock and buy more than one graphics card for their systems.
But enough of speculation. As always, you can read what is so special about the DC-to-DC technology; and to what extent its implementation into the new Tagan SuperRock TG680-U33II 680 Watt PSU has been a success. Have fun reading…

Scope Of Delivery:

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• Tagan SuperRock TG680-U33II 680 Watt in retail package
• Connector cable
• 4 screws and cable straps
• Manual (multilingual)

Technical Data:

• Casing material: Steel
• Total output: 680 Watts
• 180 Watt combined power output (+3.3 and +5 V)
• 672 Watt (56 Ampere) combined power output (+12 V)
• Voltage range: 100-240 VAC for different power grids
• Maximum power rating of the individual conductor lines:
• +3.3 V: 28 A
• +5.0 V: 30 A
• +12 V of V1: 18 A
• +12 V of V2: 18 A
• +12 V of V3: 18 A
• +12 V of V4: 18 A
• -12 V: 0.5 A
• +5 V of Standby: 4 A
• ATX versions: 2.3, EPS 12V v2.9
• EMC shielded wires
• Active PFC (99%)
• Fan: 120mm (fluid dynamic bearing)
• Cable management: no
• DC-to-DC technology: yes
• OCP - Over Current Protection
• OTP - Over Temperature Protection
• OPP - Over Power Protection
• OVP - Over Voltage Protection
• UVP - Under Voltage Protection
• SCP - Short Circuit Protection
• Standard-PS/2-dimensions (WΧHΧD): (150Χ86Χ160) mm
• Weight: approx. 2.83 kg (without packaging)
• RoSH compliant
• Current price: approx. 90, - €
• Previous types: 400, 500, 600, 680, 780, 880, 1000 Watt
• Certificates: 80+ Bronze
• Warranty: 3 years

Test System:

Intel Core 2 E8600/Intel Core 2 Extreme QX6800
Asus P5E64 WG Professional Bios 0701
Corsair XMS3 DHX PC3-12800 DDR3 4GB Dual Kit
Graphics card
2x Powercolor HD 3870 X2 Crossfire
Eizo S2100
Sound card
Sound Blaster X-Fi XtremeGamer Fatality
Hard disks containing the system
2x Western Digital VelociRaptor with 300GB (10000 rpm, S-ATA) Raid-0
Hard disk containing data
1x Samsung F1 320GB SATA II
Hard disk containing the backup
1x Samsung F1 320GB SATA II
DVD burner
Plextor PX-760 SATA
Plextor PX-810 SATA
Floppy disk drive
Scythe Combo
Computer case
Lian Li PC-A77, 4x Multiframe S2 fans @5 volt
Operating system
Dual boot system with Windows XP Professional SP3 and Vista Ultimate 64bit SP1

DC-to-DC Technology:

The term "DC voltage transformation" is not at all new, it is common concerning car electronics, generators and of course notebooks, in which this technology is already being used for years in external PSUs. Surely the campers among us would not want to miss this technology today. Because of it, it is possible to run a common CD player using the 12 Volt connector of their car.
To keep it simple: By periodic switching, a constant input voltage is converted into a different voltage value. Its outstanding efficiency which already shows when using low loads makes it interesting for PSU manufacturers, because with conventional technology it would not be possible to get close to the magical threshold of 90% efficiency.
So, how does this work in our computer power supply units?
Concerning conventional PSU technology the coil proportions in the transformer and in the memory coil have a great influence on the output voltage. This has got the essential disadvantage, that it is only possible to either increase or decrease all of the different voltage outputs (12 V, 5 V, 3.3 V) at the same time. And there is the main problem, because the biggest load jitters occur on the 12 Volt rails, whereas the 5 Volt and 3.3 Volt conductors do not show them this noticeable, and in modern computers they do not play such a big role anymore too. Instead of this the 12 Volt rails merely provide the main supply of the system.
The result is that the 12V conductor crashes under load and the 5 Volt and 3.3 Volt rails are likely to increase their voltage. This is also one of the first reasons why future PSU technology will be based upon DC-to-DC conversion. With this technology it is possible to avoid this behaviour, because a separated voltage control takes place.

In addition we requested the following image, which also shows the advantages of DC-to-DC technology:

• Very high efficiency factors are possible, because it is only necessary to convert AC to DC once.

• Higher and more stable perfomance on the +12 V rail(s), which is important for graphics cards and other power consuming components. The Tagan 680 Watt PSU provides only 8 Watt less on the +12 V rails (672 Watt) than the total output. Power supplies with conventional technology and "Combined Power" provide up to 100 Watts less on the +12 V rail. So if you want to compare them, a 680 Watt DC-DC PSU nearly resembles a 800 Watt PSU with standard technology. When looking at the power data on the identification plate of a PSU it is possible to identify the new DC-to-DC PSUs quickly, because as said before nearly the whole power output is available on the 12 V rail.

• Stability is easier to control. Concerning stability you especially have to turn your attention to the + 12 V rail, because the other voltages derive from this rail. In other words, when the + 12 V rail is stable, then practically all the other voltages are at least just as stable.

• Future-proof: Since the +12 V rail will become more and more important in the future than it already is, these power supplies meet the upcoming requirements.

• It is no longer a problem to guarantee the important tolerances of the individual rails, so the 3% tolerance for voltage stability is not only a number on paper, but real instead.

• Less ripple and noise, since the filter can work more efficiently

Of course this technology is even more complex than we explained, but we have tried to outline the topic somewhat simpler for better understanding.
As for each technology, it stands and falls with the professional implementation. In plain language, DC-to-DC does not control itself, the technicians have to know what they do…

Finish And Technology:

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This time we unpacked the box on the right side first. When looking at the casing it is not possible to discern the PSU from the 500 Watt SuperRock, but when picking it up it is a lot heavier, it weighs about 3 kg. The somewhat coarse-grained black powder coating proves to be impact- and scratch-resistant, there is no optical highlight but the whole thing is just functional which serves its purpose.
There are no additional extras, just the screws, a multilingual manual, the connector cable and 2 cable straps.
Fortunately the power switch has not been coated with plastic, and because of the pressure point you can clearly feel whether the switch is in on or off position. With 150Χ86Χ160mm the dimensions still fit the ATX standard, so there should be no problems when installing the PSU. Recesses in form of a grid at the front end minimise the air resistance of the waste heat of the PSU, which supports the effect of the fan. Luckily there are no ventilation slots at the back end of the casing; they would interfere with the airflow. Those vents are unhelpful, because as the rest of the computer also produces heat they would lead to warm air entering the PSU which is not good for its own cooling. So the finish of the casing meets high standards.

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Unfortunately this type also has no protecting and stabilizing cable sleeve for the main wires; saving money at the wrong end again. The fan grill does not protrude the PSU casing, so there should be no problems with the installation. We remember: Problems occur when the fan grill overlaps (e.g. with Cooler Master Stacker STC-T01), when it bears on the lateral or rearmost trays and the holes for the screw connection get at least one millimetre out of alignment.
If someone misses cable management, we recall our relevant advices:

1. The additional circuit boards and connections do not only represent a higher manufacturing effort and an additional cost, but also the possible risk of voltage loss caused by corrosion…

2. If many devices have to be supplied, we also need to lay many cables, therefore the optical / logistic advantage is lost…

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The PSU's fan is a hydrodynamically stored sample of ProTechnic Electric (China), the same which is used by be quiet, OCZ and Silverstone. The manufacturer data read as follows

• Identification number: MGA12012HF-025
• Storage: Fluid Dynamic Bearing (FDB)
• Weight: 180g
• Illumination: no
• Dimensions (mm): 120x120x25
• Amount of fan blades: 7
• max. loudness: 37 dBA
• max. volume transport (CFM): 80,48cfm (136.82 m ³ /h)
• max. speed: 2500 rpm
• Power input: 5.4 Watts
• Connection: 2-pin

The fluid dynamic bearing is a patent of Sony and is used in current HDTV devices for example, but also in fans e.g. by Scythe or also ProTechnic Electric. Because of the help of this bearing there is only an extremely small mechanical wear, which prevents the increase of bearing tolerances. So we can consider a great lifespan on the one hand and a calm and harmonic behaviour.
The fan blows into the PSU casing, which is very useful because it transports the waste heat out of the PSU and since it causes a suction it helps to transport the warm air away from the CPU / mainboard section.

Now we will have a look at the most important elements of a PSU, the components inside:

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The layout conforms to the current assembly of Impervio. In order to provide a rapid heat transport, the Hotspots of the Mosfets are lead to the protruding aluminium coolers via cooling plates. The form of the cooling fins is good for the airflow inside the PSU casing, it will probably avoid the development of Hotspots.
The circuit board consists of glass fiber mats which were soaked in epoxy resin. This is already upper quality class, in contrast to cheaper Pertinax circuit boards. This type of board is also used for the 780 Watt variant by the way.
Concerning the DC-to-DC technology please read the special chapter above. Impervio uses even three big electrolytic capacitors, each with 180 ΅F capacity for the primary range. They originate from Nippon Chemicon, are specified up to 105°C and thus show very high quality. The Elcaps of the secondary range predominantly come from Nippon Chemicon, Teapo, Capxon and are also specified up to 105°C. Coils and Metal oxide varistors come from the usual assortment of Japan. To cut a long story short, the selection of components shows high standards, which will reflect itself very clearly in our test.
We should take it into consideration that 105°C Elcaps have an almost twice as long lifespan compared to the 85°C Elcaps, if we like to dismiss the topic with the fact that the ATX12V Power Supply Design Guide V2.2 defines a valid operating temperature between +10 and +50°C.
Within the secondary range there is enough space left, the coils, capacitors and wires have been soldered in sufficiently large distances. Unfortunately there are no shrinking hoses at the end of the cable; it means that an important contribution to the security of a PSU is missing. Anyone who might be wondering what the plastic foils at the sides are for, they are there to prevent the device from short-circuits. The processing of the interior has been made accurately, but in detail somewhat uncharitable. The manufacturer used some silicone where it has been necessary, but it would have been nice if there was some rubber coating in order to avoid additional noise from the coils.
Of course the circuit board for the implemented protective circuits is also not missing, but you have to be careful there, because not every PSU that speaks of OCP, OVP, etc. really actively uses those circuits. There are quite a few manufacturers that leave out those circuits, even if the brochures tell a different story. But the motives for this are quite clear, the protective circuits have negative effects on the efficiency of a PSU and because they can only advertise well with high efficiency, they cheat. The customer nearly has no chance to check if the circuits are missing or not. Only when the PSU is hosed and kills all the components you get an idea of what went wrong. But do not worry, the Impervio layout has got those working protective circuits in all variants, which are present on the market at the moment:

• OCP - Over Current Protection
• OTP - Over Temperature Protection
• OVP - Over Voltage Protection
• OPP - Over Power Protection
• UVP - Under Voltage Protection
• SCP - Short Circuit Protection

Also the Tagan PSU already meets the requirements of the RoHS environmental ordinance ("Restriction of the use of certain Hazardous Substances in electrical and electronic equipment"), which came into effect in July 2006. A separate advertisement of this characteristic does not help in merchandising anymore, the manufacturers have to comply with it.

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Some wiring harnesses could be somewhat longer, but nonetheless there should be no problems because of too short cables when installing the SuperRock 680. Although the cables are coated their flexibility is very good, we already had some more stubborn samples of PSUs for our tests. The 24 pin mainboard power connector meets the requirements of the current ATX 2.0/2.2 standard and if necessary we can shorten the connector in clipping the additional 4 connectors, therefore we do not need an adapter for 20 pin mainboards.
Smaller SLI or Crossfire systems can be supplied easily with the two PCI express power connectors. The current generation of the DirectX10 graphic cards was also taken into consideration, therefore an 8-pin PCI express connector exists. Our HD3870 X2 Crossfire system however already needs both plugs for one graphics card, therefore we had to use an adapter for the test.
Maybe some users will miss a tacho sensor and temperature-controlled connectors, but we have to tell them that those are often a source for problems, because there are many mainboards that refuse to work at a rotation speed of 1.000 rpm. All important wires are insulated and coated, which does not only look good, but it helps to keep the casing neat and it minimises electromagnetic interferences.

Technical Aspects Concerning Current PSU Technology:

1. Performance specifications of PSUs:
Again and again our tests show that the manufacturer's data is not the same as the actual display of performance of a PSU!
There are lots of 450 Watt PSUs that even do not perform well under low load, which means that they do not fulfil their specifications. On the contrary there are powerful 300 Watt PSUs that provide enough power for highly upgraded systems. So it is obvious that the Watt specification says absolutely nothing about the performance of a PSU, this also applies to the data on the type label.
In order to avoid this, we best buy a quality product of a brand which provides enough power for our system, because those manufacturers use high class components in order to guarantee voltage stability and highest efficiency. To name some examples, there are Seasonic or Enermax or other companies, that let well-known manufacturers assemble their products: Enhance and Impervio assemble for Tagan, Seasonic and CWT for Corsair and Seasonic also manufactures PSUs for Silver Power. We bring this topic up in our PSU reviews in order to show you which technology is inside your desired products.
Especially among overclockers the main criteria is the stability of the several voltage rails. When you use qualitative lower or overstrained PSUs for overclocking it is possible that the voltage rails can not provide their specified power. In this case a PSU might provide 11 V instead of the needed 12 V, 4.7 V instead of 5 V or even less. While a certain tolerance is normal (see ATX V2.03 specification) and unproblematic, higher tolerances usually lead to instability and system crashes, which often are not identified as PSU problems immediately...
Basically it is like follows:
Concerning a computer PSU their specified power is often declared with the "Total DC Output" (DC is for direct current). This maximum value states how much Watt the PSU can provide on all conductors together. "Combined Power" however consists of the maximum power of the +3.3 V and the +5 V rail. If the conductors are under single load they provide more power but it decreases when all the conductors are under load.
In the past, the +12 V and +5 V rail provided the voltage for hard disks, CD-/DVD drives and floppy disk drives for example. The most important conductor was the 3.3 V rail, it powered the mainboard, the processor (CPU), the memory (RAM), the AGP bus and almost all PCI cards. Before the release of the ATX specification this so-called "I/O Voltage" was converted from the 5 V conductor. Therefore a well dimensioned PSU should provide ~30 A on the +5 V conductor and ~25 A on the +3.3 V conductor, as well as at least 200 Watt Combined Power.
This recommendation however originates from the ATX 1.3 times and has changed a lot, because in the meantime Core2 Duo/Quad and K8/K10 systems take their elixir increasingly, not to say mainly, from the 12 V conductors. At that time Intel had introduced the well-known ATX12V plug. Meanwhile the manufacturers reproduced this on the nForce 2/3/4 and Athlon K7/K8 boards and offer a 12 V plug too, this is also the case for the current 775/1366 boards. Because of the high power input of those mainboards this is a step into the right direction. Of course this +12 V rail should to be well dimensioned and provide at least 15 A per 12 V rail, the more the better.
We do not want to disregard that most Multi Rail PSUs have only virtual 12 V rails, this means that there is only one powerful 12 V source which is split up. Each conductor gets its own Over Current Protection circuit and becomes a "rail". Those are not really independent conductors, because of that they are called virtual rails. In addition there are PSUs that contain several transformers (e.g. Tagan, Enermax), therefore they also contain really separated conductors that can be controlled separately and make OCP possible.
In any case the power distribution via several conductors is a problem, because if individual 12 V rails do not provide sufficient Ampere, reputable manufacturers bundle those rails for extreme load to avoid a possible undersupply. The Intel standard does not specify this, but apparently Intel forgot what amount of current fast systems actually draw from the 12 V rail. Exactly this is also the reason, why more and more manufacturers begin to specify only one conductor in their specification sheets although there are more conductors present which have been bundled. For example Tagan offers a so-called turbo-switch in some PSU models, with which the user can handle the interconnection manually if necessary. Other manufacturers have this done automatically, and we think this is more practicable, because this way it is not the user's decision over stability or instability of the PSU.

2. Power Factor Correction (PFC):
"Power Factor Correction" or short PFC has become a mandatory EU standard for computer PSUs, in order to avoid that their current draw charges the power grid more than necessary. Switching power supplies draw current from the grid in form of short impulses, which leads to the behaviour that the grid voltage in form of a sinus wave gets distorted by the generation of harmonic waves. Altogether the complex load characteristic of a common PSU is unpropitious for the power grid, because there is a huge phase shift of voltage and current and also a high distortion of the wave shape. The larger this phase shift is, the lower the power factor of devices becomes: If the phase shift between voltage and current is 90° the power factor is 0 (0%, cos (90) = 0). If there is no phase shift at all, which means that voltage and current are perfectly synchronous, the power factor is 1 (100%, cos (0) = 1). There we have to discern the "apparent power" which we can calculate by using voltage*current from the "real power" which considers the phase angle: current*voltage*power factor. The power factor describes the proportion between the "real power" which is sent to the electrical connection and the real consumer load which is the "apparent power" (power factor = real power / apparent power). The further the power factor differs from the optimal value 1 (100%), the higher is the "idle power".
Passive PFC systems reach a power factor of up to 0,8 in suppressing the harmonic waves by means of a relatively simple, passive component. Active PFC systems take the distortion factor into consideration; this is the proportion between the basic waves and the harmonic waves. To achieve this they make use of an IC and control the current draw considering the voltage characteristic, as if a pure resistor load without phase shift (power factor = 1) had been plugged in. Therefore Active PFC achieves a significant higher power factor of over 95% and more. Additionally this circuit makes an easier adaption to all power grids from 85 to 265V possible.
Our preferred device to measure the efficiency in co-operation with an Energy Monitor 3000, is the graphic power meter Peak Tech 2535. With this equipment we can determine both real power > apparent power and also idle power and power factor.
In general PFC is a technology that shall serve the improvement of the electric power supply, in trying to adapt the complex load characteristic of devices to those of simpler devices.

3. What especially is new in the ATX12V v2.0 respectively 2.2 standard?
This is the most modern specification for desktop computer mainboards and PSUs, that contains substantial changes in comparison to the v1.3 standard:

• The SATA connections are now officially certified.
• The mainboard's main plug was extended from 20 to 24 pins, in order to be able to process the current consumption on the PCI Express bus better.
• The new specifications demand only 70% efficiency under full load and typical load (50%), under low load (idle processor) even only 60% are demanded. As a recommendation the specification names 80% under typical load, 75% under full load and 68% under low load. See also the ATX 2.2 PSU Design Guide.
• The 6 pin Aux plug has been removed.
• The circuit technology has been upgraded using dual 12 V outlets, which guarantee greater stability for CPU and peripheral devices. (see chapter 1 performance specifications)
Additionally the +12 V power output has been increased to balance the consumption of the PCI Express slot.
All of this is dull theory because current PSUs are developed to the liking of the manufacturers and for the requirements of the market. Today the ATX or Intel specification can be just seen as a suggestion in the best case. Concerning the efficiency, we are going to reach the magical threshold of 90% at the end of the year 2008, and you do not need to be a prophet for that.

4. Air ventilation, loudness and efficiency:
Nearly every box containing a new PSU has got the label "Silent", but that is just effective in advertising. Often a so-called silent PSU becomes a disturbing noise source under load. The cause for this are often not only the high driven and load controlled fans but also the noise and / or vibration that come from overstrained voltage converters.
Concerning loudness and ventilation of PSUs we can state as follows:
Modern ATX PSUs have got a efficiency of approximately 60-85% depending on quality and design. It means that when the PSU has to provide the system with 150 Watt it will result in 60 Watt of thermal energy inside the device. This considerable amount of heat has to be dissipated in order to avoid overheating which will lead to instability!
Therefore most current PSUs have got a load or temperature controlled unit (or a combination of both), which means that the fan speed will be adapted automatically - loudness increases with load respectively temperature. As an alternative there are models with manual or semiautomatic control. But we have to be careful with them: Too high sensitivity to noise often leads to overheating. Who would either not want to risk damage to his hardware or would not want to crawl behind the computer all the time in order to adapt the fan speed, would have to set the fan speed higher for security reasons. So it is rather advisable to buy a PSU with automatic fan control.
It is quite clear that a ventilation concept that demands to lead the hot air only through the PSU is problematic on both counts: First of all the PSU is cooled worse, which maybe can lead to unstable voltage rails.
Secondly the PSU fans have to run on higher speed to provide a proper cooling, which means that the amount of noise will become higher. To avoid this there is a compromise: to take a PSU fan that is able to transport a higher amount of air, for example a 120mm or 140mm fan.
Silent PSUs that have one or two slow speed 80mm fans might have no appropriate cooling performance, but there are exceptions like Seasonic or PC Power & Cooling.
Concerning the topic efficiency we have to remark that there will be no big change as long as the majority of the customers mainly considers the price, the extras and the power of a PSU and rejects to pay a bit more for energy efficiency. Apart from that we await the first 90+ PSUs, which are to be build at the end of 2008.

5. Protective circuits:
Current high-quality PSUs have numerous chip controlled protective mechanisms, in order to protect our expensive hardware against damage by short-circuits, voltage peaks and others:

• OCP (Over Current Protection) - protection from current peaks.
• OTP (Over Temperature Protection) - overheating protection.
• OVP (Over Voltage Protection) - overvoltage protection.
• OPP (Over power Protection) - overload protection.
• UVP (Under Voltage Protection) - under-voltage protection.
• SCP (Short Circuit Protection) - protection from short-circuits.
• NLO (No Load Operation) - protection from operations without load.

If your favoured PSUs do not contain most of these protective mechanisms, you should stay away from buying them, because if said problems occur these PSUs are likely to kill any attached hardware…!

6. Power Good Value:
The Power Good Value (PG) specifies the space of time in which the mainboard and the PSU "talk to each other" during the power on of the system. Parts of the mainboard are permanently supplied with +5 V via the Slave Power Supply. This is the green wire that leads from the mainboard to the PSU. When pressing the power button this voltage goes to zero, the PSU starts. When something is wrong, the PSU stops its supply and the computer resets. Under normal conditions the Power Good Value is between 100 and 500ms.

The Installation:

Exchanging the PSU is not very difficult, even unpractised users should not encounter great difficulties, therefore we do not describe the procedure in detail, and name only the important aspects.
The most important basic rule when working inside the computer casing is to set all the components to zero-voltage.
Therefore first switch off the PSU and better plug off the cable.
But the computer is not yet set to zero-voltage completely, because on the mainboard and inside the PSU there are still charged capacitors.
When operating the system these capacitors balance current fluctuations. Normally the components discharge without any action, but this can take up to 10 minutes.
Who wants to wait for such a long time? Using a small trick you can get rid of the remaining electricity: Simply press the power on button of the computer again, after the cable has been removed.
You will notice that the fans start for a split second and stand still immediately again.
Now the computer is set to zero-voltage and the old PSU can be exchanged with the new one.

Please do not forget to ground yourself before working inside the computer!

The Test:

Before the installation of a PSU and respectively before the test we briefly check its function with a Power Supply Tester. If there already are any problems, for example a fan that is not running, we cancel the test and return the PSU to the sender...
The Power Good Value (PG) specifies the space of time in which the mainboard and the PSU "talk to each other" during the power on of the system. Parts of the mainboard are permanently supplied with +5 V via the Slave Power Supply. This is the green wire that leads from the mainboard to the PSU. When pressing the power button this voltage goes to zero, the PSU starts. When something is wrong, the PSU stops its supply and the computer resets. Under normal conditions the Power Good Value is between 100 and 500ms, which also was the case concerning the Tagan PSU with 270ms.

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After ending our 12 hour stress test (Prime95 and 3DMark2005 in a loop), we could compare the measured values of our test software (Everest 4.60, SiSoftSandra XII 2008 SP2c and HWMonitor 1.12) and we averaged them to get a better error correction. We also measured the values with a Fluke 179 multimeter directly at the mainboard and compared them to the values of the programs. Of course the values that come from the multimeter are of a higher relevance than those coming from the software.
We determined the efficiency with the help of a graphic power meter Peak Tech 2535 and an Energy Monitor 3000 made by Voltcraft.
The loudness of the fans has been measured with an ACR-264-plus analyzer at a distance of approximately 15cm. The ambient noise has been reduced as much as possible before, in order to avoid a falsification of the results. According to DIN standard the distance from the analyzing instrument to the test object should be about 100cm, but since we do not have an anechoic room we had to make a compromise.
With the Digital Temperature Gauge TL-305 we measured and stored the temperature of the exhaust air during all the test routines. Therefore the potential customer also gets a good overview concerning the complete cooling performance of the PSU.
With the Seasonic Power Angel it was possible for us to determine the PFC values and to compare them to the values of the Peak Tech 2535.

The ATX V2.03 specification permits the following limit values:

Output Tolerance Umin. UNom. Umax.
[%] Volt Volt Volt
+12 V* 5 11.4 12.00 12.60
+5V 5 4.75 5.00 5.25
+3.3V 5 3.14 3.30 3.47
-5V 10 4.50 5.00 5.50
-12V 10 10.80 12.00 13.20
+5Vsb 5 4.75 5.00 5.25

The test values of the Tagan SuperRock TG680-U33II 680 Watts Power Supply:

Performance category
lowest value
highest value
average value

further test results
Category: 20% load 50% load 80% load full load
Temperatures 32.5°C 35.5°C 40.5°C 43.5°C
Loudness of the fan in dBA 18.5 dBA 21.5 dBA 26 dBA 29.5 dBA
Perception of the fan scarcely audible very quiet quiet still quiet
PSU electronics noises none none none none
Efficiency (230VAC) 83.5% 85.5% 87.5% 82.5%

Who is worrying about the slim 180 Watt combined power for the 3.3 V and 5 V rails, is thinking the wrong way, because current systems draw their power mainly from the 12 V rails, where this PSU provides 672 Watt (56 Ampere). This and the DC-to-DC technology is normally more than enough for every desktop computer system.
The tolerances of the rails of the Tagan SuperRock TG680-U33II 680 Watt add up to very good 3%, current technology makes tolerances from 1 to 3% for the 12 V/5 V and 3.3 V rails possible, PSUs with low-grade components reach 5% in the best case.

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Our system with the good old "current saver" Intel Core 2 Extreme QX6800 and two HD2870 Crossfire graphics cards demanded 635 Watt (and a maximum of 710 Watt overclocked) under load from the PSU, so that we could test very well whether it still has got any reserves at its limit range. With further overclocking and 770 Watt power requirement the protective circuits were activated, which is completely correct and working as intended. A no-name product does not offer this, which is a further evidence for the perfectly implemented DC-to-DC PSU technology.
As always the note: Please do not try this at home!
The loudness of the fan without load, 18,5 dBA at 745 rpm, was subjectively not to be noticed, in this state the fan needs 4.4 V. Under load and starting from approximately 400 Watt the noise situation becomes somewhat different, here the maximal value was 30.5 dBA at 1390 rpm, which however is still acceptable, because its noise is drowned out by other active fans. In the high load range the PSU needs appropriate ventilation, which can not be achieved completely noiselessly.
The PSU electronics kept quiet, we could only hear a faint whirring coming from the fan. There were no static noises during our tests. The fan also works quietly; there were no noises from the bearing for example. The cooling of the PSU is very good, thanks to a 120mm fan and optimized air flow. In idle mode the temperatures came to very good 32.5°C, under load they increased to 43.5°C, which clearly shows the good cooling of this PSU. With 20%, 50% and 80% load, as already explained in the table, we could see an efficiency of 83.5, 85.5 to a maximum of 87.5% under 80% load, which is an excellent result. Beyond that the device consumes 0.65 Watt in standby mode (computer switched off), which is a likewise very good value.

An additional explanation for the dBA definition:
A human's hearing in general is best at 1.000 Hz, the dBA value refers to it: a sound at 18.000 Hz is sensed more faintly than a sound at 1.000 Hz, and the dBA value corresponds to this.

We have to advise you that the results which appear in this review refer only to our test system without exception…

The Most Important Performance Data, Efficiency And Temperatures Of Currently Tested PSUs In Comparison:

Power Supply Unit Ψ Voltage max. Efficiency Temp-Idle Temp-Load
Akasa Ultra quiet 80+ 500Watt 3.36V 5.08V 12.05V 82.5% 34.5° 43°
Amacrox Free Style 750 Watt 3.28V 4.93V 11.99V 85% 33.5° 44°
be quiet! P7 Dark Power Pro 550Watt 3.31V 5.09V 12.08V 87% 33° 43°
be quiet! Straight Power BQT ES-600Watt 3.34V 5.04V 12.07V 79.5% 32° 45°
Cooler Master Silent Pro M-Series 600Watt 3.36V 4.90V 12.16V 87% 33.5° 44.5°
Corsair CX400W 400Watt 3.30V 4.88V 12.01V 85.5% 33.5° 43°
Corsair HX620W 620Watt 3.32V 5.05V 12.08V 83.5% 35° 44.5°
Corsair HX1000W 1000Watt 3.36V 5.05V 12.07V 86.5% 39.5° 50.5°
Corsair TX650W 650Watt 3.29V 4.97V 12.02V 84.5% 34° 42°
Corsair TX750W 750Watt 3.27V 5.06V 12.11V 84.5% 44° 53°
Corsair VX450W 450Watt 3.25V 4.96V 12.13V 84% 46° 55°
Corsair VX550W 550Watt 3.27V 4.91V 12.18V 83.5% 41° 48°
Enermax Liberty ELT 620Watt AWT 3.36V 5.09V 12.13V 79% 34° 45°
Enermax Infiniti 720Watt 3.37V 5.07V 12.19V 85.5% 31° 43°
Enermax Modu82+ 625Watt 3.32V 5.04V 12.11V 86.5% 33° 43.5°
Enermax Pro82+ 385Watt 3.33V 5.02V 12.05V 85.5% 34° 44.5°
Mushkin HP-580AP 580Watt 3.26V 4.94V 12.32V 81.5% 34° 44°
Mushkin EP-500AP 500Watt 3.35V 5.06V 12.06V 82.5% 32.5° 42.5°
Mushkin XP-650 650Watt 3.32V 5.01V 12.11V 81% 35.5° 45°
Nexus NX-8050 500Watt 3.27V 5.01V 12.24V 82.5% 35.5° 45.5°
Seasonic S12 Energy Plus 550Watt 3.34V 5.03V 12.05V 84.5% 32° 42°
Seasonic M12 II 430Watt 3.37V 5.14V 11.92V 86.5% 32.5° 42.5°
Seasonic S-12 II 500Watt 3.35V 4.99V 12.05V 87% 33° 43°
Seasonic X900 900Watt 3.34V 5.04V 12.22V 86.5% 32° 41°
Silver Power SP-SS400 400Watt 3.29V 4.86V 12.02V 85.5% 33° 42.5°
Silver Power SP-SS500 500Watt 3.31V 4.90V 11.99V 86.5% 33° 43.5°
Silverstone Decathlon DA 750Watt 3.39V 5.16V 12.20V 82% 34° 44°
Silverstone Element ST40EF 400Watt 3.29V 5.09V 12.30V 85% 32° 42°
Silverstone Element ST50EF 500Watt 3.32V 5.01V 12.10V 81% 32° 44°
Silverstone Nightjar ST45NF 450Watt 3.30V 5.12V 12.15V 84.5% 45° 57.5°
Silverstone Olympia OP 650Watt 3.36V 4.99V 12.10V 82.5% 33.5° 43.5°
Silverstone Strider ST35F 350Watt 3.35V 5.02V 12.30V 82.5% 38° 46°
Silverstone Strider ST56F 560Watt 3.39V 4.90V 12.22V 80% 31° 43°
Silverstone Strider ST60F 600Watt 3.35V 5.03V 12.34V 78% 31° 42°
Silverstone Strider ST75F 750Watt 3.34V 5.02V 12.30V 81% 30° 40°
Silverstone Strider ST85F 850Watt 3.31V 5.09V 12.05V 81% 32.5° 41.5°
Silverstone Zeus ST56ZF 560Watt 3.31V 5.08V 12.19V 76% 34° 45°
Silverstone Zeus ST75ZF 750Watt 3.31V 4.98V 12.06V 79% 30° 42°
Tagan TG600-BZ Piperock 600 Watt 3.29V 4.99V 12.14V 85.5% 32.5° 42.5°
Tagan TG1300-BZ Piperock 1300 Watt 3.31V 5.01V 12.18V 86% 30.5° 41.5°
Tagan TG500-U33II SuperRock 500 Watt 3.32V 5.02V 12.14V 86.5% 31.5° 42.5°
Tagan TG680-U33II SuperRock 680 Watt 3.38V 5.02V 12.18V 87.5% 32.5° 43.5°
X-Spice Croon 550 Watt 3.31V 4.97V 12.34V 84.5% 34.5° 45°

Power Supply Unit dBA-Idle dBA-Load Standby-Consumption Price
Akasa Ultra quiet 80+ 500Watt 23.5 dBA 26.5 dBA 7.3 Watt 89.90 €
Amacrox Free Style 750 Watt 18.5 dBA 27.5 dBA 1.7 Watt 129 €
be quiet! P7 Dark Power Pro 550Watt 18.5 dBA 23 dBA 0.9 Watt 130 €
be quiet! Straight Power BQT ES-600Watt 20 dBA 29 dBA 1.5 Watt 99.90 €
Cooler Master Silent Pro M-Series 600Watt 19 dBA 27.5 dBA 1.15 Watt 99.90 €
Corsair CX400W 400Watt 19.5 dBA 27 dBA 0.8 Watt 49 €
Corsair HX620W 620Watt 23.5 dBA 26 dBA 1.2 Watt 130 €
Corsair HX1000W 1000Watt 25.5 dBA 38.5 dBA 1.6 Watt 170 €
Corsair TX650W 650Watt 24.5 dBA 31.5 dBA 1.3 Watt 105 €
Corsair TX750W 750Watt 28.5 dBA 38.5 dBA 1.6 Watt 130 €
Corsair VX450W 450Watt 21 dBA 25 dBA 0.9 Watt 89 €
Corsair VX550W 550Watt 22.5 dBA 27 dBA 1.05 Watt 105 €
Enermax Liberty ELT 620Watt AWT 27 dBA 32 dBA 1.9 Watt 169 €
Enermax Infiniti 720Watt 26 dBA 37 dBA 1.9 Watt 214 €
Enermax Modu82+ 625Watt 18.5 dBA 28.5 dBA 0.95 Watt 129 €
Enermax Pro82+ 385Watt 17.5 dBA 26.5 dBA 0.85 Watt 59 €
Mushkin HP-580AP 580Watt 23.5 dBA 36.5 dBA 2.2 Watt 90 €
Mushkin EP-500AP 500Watt 21.5 dBA 29.5 dBA 1.45 Watt 55 €
Mushkin XP-650 650Watt 25 dBA 30 dBA 1.3 Watt 104 €
Nexus NX-8050 500Watt 22.5 dBA 26 dBA 1.1 Watt 125 €
Seasonic S12 Energy Plus 550Watt 23 dBA 25 dBA 0.5 Watt 140€
Seasonic M12 II 430Watt 19.5 dBA 27.5 dBA 0.6 Watt 85 €
Seasonic S-12 II 500Watt 22 dBA 25.5 dBA 0.7 Watt 90 €
Seasonic X900 900Watt 22 dBA 33 dBA 1.6 Watt 249 €
Silver Power SP-SS400 400Watt 19.5 dBA 27.5 dBA 0.75 Watt 59 €
Silver Power SP-SS500 500Watt 19 dBA 29.5 dBA 0.8 Watt 79 €
Silverstone Decathlon DA 750Watt 24.9 dBA 33 dBA 2.2 Watt 179 €
Silverstone Element ST40EF 400Watt 24 dBA 29 dBA 1.8 Watt 79 €
Silverstone Element ST50EF 500Watt 27 dBA 32 dBA 2.5 Watt 88 €
Silverstone Nightjar ST45NF 450Watt 0 dBA 0 dBA 1.25 Watt 145 €
Silverstone Olympia OP 650 Watt 24.5 dBA 33.5 dBA 1.9 Watt 148 €
Silverstone Strider ST35F 350Watt 25.5 dBA 28 dBA 1.3 Watt 59 €
Silverstone Strider ST56F 560Watt 29 dBA 33 dBA 5 Watt 114 €
Silverstone Strider ST60F 600Watt 31 dBA 36 dBA 9 Watt 144 €
Silverstone Strider ST75F 750Watt 29 dBA 35 dBA 4 Watt 165 €
Silverstone Strider ST85F 850Watt 24 dBA 35.5 dBA 1.9 Watt 225 €
Silverstone Zeus ST56ZF 560Watt 32 dBA 41 dBA 7 Watt 120 €
Silverstone Zeus ST75ZF 750Watt 27 dBA 33 dBA 3 Watt 183 €
Tagan TG600-BZ Piperock 600 Watt 20.5 dBA 25.5 dBA 1.2 Watt 95 €
Tagan TG1300-BZ Piperock 1300 Watt 26.5 dBA 40.5 dBA 2.7 Watt 250 €
Tagan TG500-U33II SuperRock 500 Watt 19 dBA 28.5 dBA 0.55 Watt 60 €
Tagan TG680-U33II SuperRock 680 Watt 18.5 dBA 30.5 dBA 0.65 Watt 90 €
X-Spice Croon 550 Watt 20 dBA 26.5 dBA 3.1 Watt 90 €

The Top Ten Of The Power Supply Units Tested So Far (Updated):

Requirements for the admission to this list:

1. The PSU has to be currently available

2. There has to be a current revision

3. If a PSU series contains several models, we add the one to the list which appears to be the best in our opinion

The products on this list are not primarily directly comparable, because they often have different performance classes and concepts…

Power Supply Unit Toplist:
Tagan Superrock TG680-U33II 680 Watt
Enermax Modu82+ 625 Watt
Cooler Master Silent Pro M-Series 600 Watt
Tagan Superrock TG500-U33II 500 Watt
Enermax Pro82+ 385 Watt
Silverstone Nightjar ST45NF 450 Watt
Seasonic S12 II 500 Watt
Corsair HX1000W 1000 Watt
Silver Power SP-SS500 500 Watt
Silver Power SP-SS400 400 Watt


You may please forgive us our little Crossfire Extreme test, but when there is new technology we are itching to test it under stability limit conditions. The DC-to-DC technology has been perfectly implemented by Tagan respectively Impervio, and we were thinking that this is by no means the end of the line.
The Tagan SuperRock TG680-U33II 680 Watt Power Supply Unit performs with greatest stability in each load condition, is has an excellent efficiency and an acceptable loudness. There are no additional extras which seems to be a bit contrariwise and the consumers that pay attention to exterior design would not find something special about it, but this should be one of the minor reasons for buying a PSU.
Here are the most important results and facts of our test in a short summary again:

• outstanding finish
• extremely robust lacquering
• outstanding efficiency (under 20%, 50% and 80% load)
• excellent stability and supportive time
• outstanding low voltage tolerance values
• correctly responding protective circuits
• DC-to-DC technology
• very good active PFC values
• very good cooling
• very high power reserves
• extremely smooth running and balanced fan
• no interferences coming from the PSU electronics
• good integration of the PSU into the cooling management of the computer case
• mostly more than sufficient cable lengths (over 50cm)
• very effective cable shielding and insulation
• 105°C capacitors in primary and secondary range
• good cost/performance ratio (approx. 90. - €)

• some wires could be somewhat longer
• no additional extras

Now, who should buy such a Power Supply Unit? All those users, who need sufficient reserves, in order to overclock their systems or to run Crossfire/SLI, may call themselves potential buyers. For all the others, the smaller variants provide enough power, and those are the masses of users, even if they glance enviously at this piece of excellent computer hardware…

Overall Total Result Of Our Review:

The Tagan SuperRock TG680-U33II 680 Watt Power Supply Unit receives the PC-Experience Technology Award in Gold

Additional weblinks:


Our sincere thanks go to Maxpoint for the supply of the test sample and for the kind support.

your PC-Experience.de Team


Forensoftware: Burning Board , entwickelt von WoltLab GmbH