Corsair AX750 80 Plus Gold: Putting Corsair's Best to the Test
by Martin Kaffei on November 30, 2010 12:00 AM EST- Posted in
- Cases/Cooling/PSUs
- Corsair
- PSUs
- 80Plus Gold
- 750W
Conclusion
The Corsair AX750 is the best PSU Corsair sells at the moment, and it shows. It has no problems reaching 80 Plus Gold levels, and with 230VAC it even exceeds Gold requirements. 91% at 50% load is not too shabby.
When you open the Corsair PSU you can see a clean Seasonic design with all solid capacitors from Nippon Chemi-Con, a well chosen line filtering stage in the entrance (Delta), and many surface mounted devices on the PCB. A modern Champion IC in combination with an Infineon switcher are a very common picture for high-end PSUs and deliver a proven quality. ZVS and DC-to-DC are the reason for the high efficiency. Corsair is using the best modern technology, and the AX750 delivers.
Throughout the review, we could only come up with a few minor points of criticism. First, the fan connector could be glued down. Second, the fan grille on the nice black case protrudes a little. About the only real potential concern is trying to utilize all of the Molex and SATA connectors in larger tower cases; you'll want to check the case layout before going that route, although that's definitely a niche market. When that's the worst we can come up with, there's obviously very little wrong with the AX750.
At 10% load Corsair reached 82% efficiency, which is nice to see. Similarly, there is almost no ripple or noise on the rails--+3.3V for example is always under 13mV. The other rails have slightly higher results, but in all cases they're under 20mV. The voltage regulation for +3.3V and +5V could be a little bit better, as both rails drop below 3.60%, but realistically the 12V rail is the important criterion and +12V is just 0.25% under the optimal value.
The delivery contents include 12 SATA connectors on four cables (more than the older Seasonic X-750) and four 6/8-pin PCIe connectors with a black sleeving. The 60cm primary cables are sufficient for most cases, you get two floppy-adapters (just in case), a bunch of cable ties to help you clean up the installation, and flat peripheral cables.
As already mentioned in the introduction, you have to pay more for the older Seasonic X-750 than for the new Corsair AX750. Corsair offers the same quality with flat cables for a lower price. The OCZ Z-Series 80Plus Gold OCZZ850M is no match for Corsair as well, because the efficiency is lower and the soldering quality worse. One potential contender we see is the upcoming HCP series from Antec, which will start at 750W. Otherwise we have to wait for the Seasonic X-760, which should be available shortly.
What we can tell you is that right now, the Corsair AX750 provides a great set of features in a stylish package for a very good price. Yes, you can find less expensive options, and if you get a good sale price you can even get a quality PSU for under $80. However, realistically you're looking at spending over $100 if you want 80 Plus Gold, and not all Gold PSUs are created equal. Silence, performance, quality, and an attractive price make the AX750 very difficult to beat. This is easily one of the best power supplies on the market right now, and for that we're presenting Corsair with our Gold Editors' Choice award. You can get similar performance and quality, but the pricing is usually higher and unless you like waiting to see what the competition can bring to bear, this is a great high-end PSU.
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Chapbass - Tuesday, November 30, 2010 - link
On the cables and connectors page: last para:The only potential issue is if you want to load up all we SATA connectors with a bottom-mounted PUS; the distance from the PSU to the first connector is only 45cm (give or take), with a fairly large 12-13cm gap between the connectors, so you'd want the HDD bays to be relatively close to the PSU rather than in the top portion of the case.
First sentence has a few typos. Still reading, but figured I'd point it out.
Shadowmaster625 - Tuesday, November 30, 2010 - link
Aren't all PUS's bottom mounted?Stuka87 - Tuesday, November 30, 2010 - link
Many newer cases do use a bottom mounted CPU, but it is hardly the only form factor.Stuka87 - Tuesday, November 30, 2010 - link
CPU should be PSU. Wish there was an edit :/Iketh - Wednesday, December 1, 2010 - link
pretty sure they're rear-mounted when bent overNintendesert - Tuesday, November 30, 2010 - link
Last page, first paragraph."Gold requirements. 91% at 50% load is not to shabby."
It should be "too shabby."
Chapbass - Tuesday, November 30, 2010 - link
Gotta say this PSU looks impressive. I'm going to need something soon for my server (not much in the way of cpu and video power, but along the lines of 18-20 HDD's), and something like this might fit the bill. we'll have to see :)props to corsair, another solid unit.
prince34 - Tuesday, November 30, 2010 - link
I've been looking for a new high quality PSU for a new build early next year. This looks very promising. Also, Newegg has a $20 mail in rebate and $15 promotional code with free shipping. Thats $135 up front and $115 in the end. That is hard to beat.mino - Tuesday, November 30, 2010 - link
This left me puzzled though:"The AX has DC-to-DC for the smaller rails, so +12V feeds +3.3V/+5V and you can't use the whole 62A there."
I know of exactly ZERO XXX-watt power supplies where you can load 3.3V or 5V _in_addition_to_ the XXX watts being consumed on 12V rails.
Actually, most PSU's on the market do not allow anywhere near 99% of its rated load purely via 12V rails like this one. So if anything, such an arrangement should considered a plus.
Beenthere - Tuesday, November 30, 2010 - link
These days there are lots of PSUs to chose from and the devil seems to be in the details. History has shown that Seasonic can produce good PSUs under their own brand and for other companies but that not all PSUs from them are not equal in design or performance.Without knowing exactly what the hardware differences are between PSUs and how this impacts performance or reliability makes it challenging when purchasing a new PSU. I watch hardware sites for patterns of issues with specific PSU models and brands when I'm looking for a new PSU.