Corsair AX 1200w ATX PSU Review

Conclusion

Just when it looked like the rest of the PSU market was finally catching up to the highly acclaimed HX series, Corsair have come out with yet another PSU range that moves the bar even further out of their sight. Without any shadow of doubt the AX1200 is by far the best PSU that has come through OC3D's labs to date, and the very fact that Corsair designed the unit from the ground up makes that achievement a whole lot more meaningful.

Starting with the efficiency, the AX1200 lives up to its 80Plus Gold certification by providing up to 93% efficiency at 600-900w loads and around 90% efficiency at all other load levels. In fact, the AX1200 is pretty much tapping on the door of an 80PLUS Platinum certificate, which is very impressive indeed.

Then there's the ripple results....well more precisely, the lack of them. 22mV of ripple on the +12v rail when the load tester is pulling over 85A through it is simply awesome. No scratch that, it's phenomenal. Only when the PSU is pushed way beyond its rated output does the ripple on any of the rails start to budge, but even then we're only talking 25-30mV on the +3.3/5v rails and 42mV on the +12v rail which is better than most other PSU's can hope to get at ordinary load levels.

The only area for any improvement (and this is me being picky) is in the stability of the +3.3v and +5v rails. While both are more than acceptable with only 0.13v drop from idle to full load, I can't help but feel that with the AX being Corsair's new flagship model, these could have been made a little more solid. That said though, the stability of the all-important +12v rail is perfect. No massive over-volting at idle, no drooping below the +12.00 marker and solid results under cross-load and maximum load situations.

Did I also mention that it is capable of holding a 1522w load at 50°C and even peaking at 1600w for a minute or two? Yum.

At the end of the day the AX1200 is an all-round belter of a PSU. It's got the looks, the performance, the warranty and even the packaging. The price is at the high end of what I'd consider acceptable for any wattage PSU (£245 @ Scan), but you get what you pay for and this certainly rings true for the AX1200. 

The Good
- Absolutely amazing ripple suppression.
- Extremely powerful +12v rail.
- Gold level efficiency only a whisker away from Platinum.
- Fully modular for those neat freaks.
- Lovely modular cables.
- Silent (as far as I could tell with 3000w of testing equipment in the background!).
- Shuts down safely when overloaded (which kicks in at over 1500w!).
- Well packaged.
- 7yr Warranty.

The Mediocre
- +3.3v and +5v rails could be a little tighter

The Bad
- Not a sausage.

In recognition of the AX1200's excellent all-round performance, I am pleased to award it our coveted "Best In Class" award for Power Supplies rated from 1000-1500w.

Thanks to Corsair for providing the AX1200 for review. Discuss in our forums.