Running the numbers
Our testing procedures can be found at this link.
Efficiency
| Load | 10pc | 25pc | 50pc | 75pc | 100pc |
|---|---|---|---|---|---|
| Efficiency | 78.5pc | 88.2pc | 89.6pc | 87.4pc | 85.0pc |
Efficiency is very good for a Bronze-rated supply. It actually meets the criteria for Silver, according to our findings. The ratings are marginal, meaning Corsair probably can't market all GS800 supplies as 80 PLUS Silver.
Regulation
In terms of regulation, we're looking at just how well the supply is able to hold to the various lines. The ATX spec. has a +/- 5 per cent leeway on all but the -12V line.
| Line/Load | 3.3V | 5V | 12V |
|---|---|---|---|
| 10 per cent | +1.1pc | +1.0pc | +1.6pc |
| 50 per cent | -0.5pc | 0pc | +0.3pc |
| 100 per cent | -2.2pc | -1.3pc | -0.8pc |
Most supplies over-volt with little load and under-volt when stressed. The same is true of the GS800. The maximum leeway is less than half that imposed by the ATX specification and, taken from peak to low, doesn't vary by more than 3.3 per cent (3.3V). Nothing to complain about here.
Regulation - cross-load
How about providing uneven loads that stress particular voltage rails? In the first attempt, we've put 60A on the 12V rails, and 1A on the 3.3V and 5V rails. This can actually be somewhat typical for a system heavy on graphics and CPU power. In the second, we've turned the tables and gone for 12A on both the 3.3V and 5V rails - highly unlikely in a real-world environment - and just 2A on the 12V - even more unlikely!
| Line/Load | 3.3V | 5V | 12V |
|---|---|---|---|
| Cross-load 12V focus | +1.4pc | +1.3pc | -0.8pc |
| Cross-load 3.3V/5V focus | -2.5pc | -1.6pc | +1.4pc |
Hammering one part of the PSU power delivery while using just a small portion of the other can throw cheaper supplies of out kilter. Maximum variation of 3.9 per cent occurs on the 3.3V line; we're content with seeing anything below five per cent here.
Ripple
| Line/Load (mv - p-p max) | 3.3V | 5V | 12V |
|---|---|---|---|
| 10 per cent | 18mV | 20mV | 15mV |
| 50 per cent | 20mV | 25mV | 20mV |
| 100 per cent | 25mV | 25mV | 50mV |
The ATX v2.2 spec states that the maximum permissible ripple is 120mV for the 12V line and 50mV for others.
PSUs convert AC power into DC, but doing so requires the AC waveform to be suppressed. What we're really testing here is the quality of the supply's rectifier and any smoothing capacitors in getting rid of this unwanted up-and-down ripple.
Per-line ripple is half of what the ATX specification permits. The 12V ripple at full load is usually the worst figure, with AC suppression being hardest to control under this load, but the GS800's 50mW is admirable for a mainstream supply.
Temps
| Temperatures | Intake | Exhaust |
|---|---|---|
| 10 per cent | 26°C | 43°C |
| 50 per cent | 30°C | 37°C |
| 100 per cent | 35°C | 46°C |
The fan isn't activated until the load hits 20 per cent and this is why the PSU is actually cooler at 50 per cent load than at 10 per cent. That said, a 43°C exhaust temperature is well within the remit of the GS800, which is rated to perform to specifications at an ambient 40°C.