The results
Efficiency
| Load | 10pc | 25pc | 50pc | 75pc | 100pc |
|---|---|---|---|---|---|
| Efficiency | 85.3pc | 90.1pc | 92.8pc | 90.3 | 89.2pc |
The 10pc load equates to around 125W of load - it's not an exact figure as the various lines have to be loaded with particular amps/volts that may not exactly map out to the desired number.
Reiterating a point that we've made before, a sub-150W figure is actually rather important to know, mainly because our Intel Core i7 2600K platform, constituting a complete PC, idles below 60W. Though we fully understand a PSU of this capacity and price is likely to be taxed with genuine wattage-guzzling components, pay close attention to the 10pc and 25pc numbers for everyday use.
The efficiency figures are top-notch across the load range, maintaining over 90 per cent in the 25pc to 75pc spectrum. We don't view ultimate efficiency as the most-important metric; even 80 PLUS Bronze-certified supplies are good enough in this regard. Regulation is more important in our book.
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 | +0.5pc | +0.8pc | +0.6pc |
| 50 per cent | +0.2pc | +0.7pc | -0.2pc |
| 100 per cent | 0pc | +0.4pc | -0.4pc |
Numbers are shown with a percentage rating of just how close the Chroma reading is to the ideal. In a word, excellent. The voltages barely move from the prescribed numbers. Indeed, it's scary-good at keeping the figures at rock-solid levels. Very impressive.
Regulation - cross-load
How about providing uneven loads that stress particular voltage rails? In the first attempt, we've put 90A 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 20A 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 | 0pc | +0.8pc | -0.2pc |
| Cross-load 3.3V/5V focus | -0.3pc | +0.1pc | -0.3pc |
The numbers are, again, excellent. The XFX/Seasonic beast is a regulation maestro. It's practically impossible to make it budge by 1pc on any voltage line. We made the supply hotter by putting it in a homemade enclosure - a padded cardboard box; yup, high-tech, we know - and increased the ambient temperature to around 40°C after loading up the supply. Regulation remained excellent throughout, showing the Seasonic design's worth.
Ripple
| Line/Load (mv - p-p max) | 3.3V | 5V | 12V |
|---|---|---|---|
| 10 per cent | 15mV | 15mV | 20mV |
| 50 per cent | 15mV | 20mV | 20mV |
| 100 per cent | 20mV | 25mV | 45mV |
The ATX v2.2 spec states that the maximum permissible ripple is 120mV for the 12V line and 50mV for others.
Ripple ranges from very good to good. Really pushing the supply with lots of 12V shows clear ripple, but it's kept firmly ensconced between the 25mV barriers at all times - and well within spec. In fact, it's only at near-100pc load that the ripple is of note on the 'scope. The numbers aren't perfect - you'd need no ripple for that, which is impossible - but all are very good.
Temperatures
| Temperatures | Intake | Exhaust |
|---|---|---|
| 10 per cent | 31°C | 34°C |
| 50 per cent | 33°C | 37°C |
| 100 per cent | 36°C | 48°C |
Decent-enough temps all round. You'd expect it to become warmer when loaded to 100pc for extended periods.
We'd normally report the noise rating, but such is the din produced by the Chroma machine - ears are still ringing - that doing so would be completely pointless.
The supply is silent at low-load levels, thanks to the 'hybrid' technology, though it requires a very low ambient temperature to kick into fanless mode - we had to engineer it. Given a more-reasonable 50pc load and a 25°C ambient temperature the fan sound is noticeable but not irritating. Increase this to an all-out 100pc and, while clearly audible if listening intently, the unit's fan doesn't produce an annoying pitch.
Results recap
A high-quality PSU with solid results to back up Seasonic/XFX's engineering.
