Test Setup

All measurements are performed utilizing ten electronic loads (seven Array 3711A, 300W each, and three Array 3710A, 150W each), which are able to deliver over 2500W of load and are controlled by a custom made software. We also use a DS1M12 (Stingray) oscilloscope, a CHY 502 thermometer, a Fluke 175 multimeter and an Instek GPM-8212 power meter. Furthermore, in our setup we have included a wooden box, which along with a heating element is used as a Hot Box. Finally, we have at our disposal two more oscilloscopes (Rigol 1052E and VS5042) and a CEM DT-8852 sound level meter. In this article you will find more details about our equipment and the review methodology we follow.

Voltage Regulation Charts

The following charts show the voltage values of the main rails, recorded over a range from 60W to the maximum specified load, and the deviation (in percent) for the same load range.

5VSB Regulation Chart

The following chart shows how the 5VSB rail deals with the load we throw at it.

Efficiency Chart

In this chart you will find the efficiency of TTB800G at low loads and at loads equal to 20-100% of PSU's maximum rated load.

Voltage Regulation and Efficiency Measurements

The first set of tests reveals the stability of voltage rails and the efficiency of TTB800G. The applied load equals to (approximately) 20%, 40%, 50%, 60%, 80% and 100%, of the maximum load that the PSU can handle. In addition, we conduct two more tests. In the first we stress the two minor rails (5V & 3.3V) with a high load, while the load at +12V is only 2A and in the second test we dial the maximum load that +12V can handle while load at minor rails is minimal.


High operating temperatures do not scare this fellow, but unfortunately after about 45°C ambient the fan kicks in really hard and outputs significant noise.
Regarding efficiency, it is high enough but we have seen Gold PSUs with much higher efficiency overall. For example at full load efficiency drops below 87%, the 80 Plus Gold threshold (115V power input - PSUs certified for desktop PCs), even though we test with 230V where efficiency is usually 1-1.5% higher than with 115V power input. However all PSUs are tested at 23°C for 80 Plus certification while we test at 50°C, so differences in efficiency - at least to some degree - are natural.

In the following table you will find the data we gathered through iPower Meter.


As you can see almost at all cases the Watt readings and the Amps per rail are very accurate. Unfortunately this is not the case for efficiency and especially for voltage readings. All in all we found very cool this little gadget since with it a user can be informed in real time about the load that his system pulls from the PSU. Also it will come in really handy to many users out there (at least to ones that want to know every detail about their system's power consumption) since it gives a very close estimation of the Amps drawn per rail. Bottom line, we were impressed by the accurate Watts/Amps readings but should note here that the 5V and 3.3V Amp readings are reversed so the 5V rail shows the 3.3V Amps and the opposite. This is a small error but not so easy to fix to already purchased units.

Efficiency at Low Loads

In the next tests, we measure the efficiency of TTB800G at loads much lower than 20% of its maximum rated load (the lowest load that the 80 Plus Standard measures). The loads that we dial are 40, 60, 80 and 100W (for PSUs with over 500W capacity). This is important for scenarios in which a typical office PC is in idle with power saving turned on.


Efficiency at low loads is quite good, taking into account that we have an 800W PSU under test and knowing that as the capacity increases, efficiency at low loads decreases.

Let's check now the iPower Meter's readings.


Voltage readings and efficiency measurements of the iPower device are far from accurate but total Watts calculation and the Amps per rail, except test#1, are really close to the real values.

5VSB Efficiency

ATX spec states that the 5VSB standby supply's efficiency should be as high as possible and recommends 50% or higher efficiency with 100mA load, 60% or higher with 250mA load and 70% or higher with 1A or more load.
We will take four measurements, three at 100 / 250 / 1000 mA and one with the full load that 5VSB rail can handle.


In the first two tests efficiency at 5VSB is a little lower than the ATX recommended levels, however in the last two tests it surpasses the corresponding levels. Overall decent performance here but surely not even close to the best we have seen so far.

Power Consumption in Idle & Standby

In the table below you will find the power consumption and the voltage values of all rails (except -12V), when the PSU is in idle mode (On but without any load at its rails) and the power consumption when the PSU is in standby (without any load at 5VSB).


With 0.62W phantom power in standby the ErP Lot 6 requirements are easily met. Also pay attention to the high voltage at the +12V rail in idle, although in a real system the PSU will never be in idle mode.