We recently looked at lower performing power supplies ranging from 400W to 450W. While some of those offerings work well, the reality is that they're not much cheaper to produce than slightly higher rated models, so most of that market is falling to the low quality, budget manufacturers. We return this week to higher performing PSUs rated at 730W to 900W that are more suited for high-end systems running more than one graphics card. It's important to have the proper connectors - and a sufficient quantity of connectors - along with a good distribution of power across the rails. Nobody running a higher end system enjoys crashes in the middle of a gaming session, after all. We have quite a few models to test from several companies, including four 850W PSUs.

Also included is one model that officially only supports a 200VAC to 240VAC input. This PSU is for the European market, but we still found it very interesting. We are talking about the Seasonic X900, but Seasonic also serves as the ODM for other brands, several of which we have reviewed. Whether or not the Seasonic X900 shows up in the US under that name, we will almost certainly see it in some form.

Note: If you would like to know more about our testing methodology, equipment, and environment, please read our PSU testing overview.

As previously stated, we now test with an additional 10% load beyond the rated output to see how the units cope with overload situations. We begin overload testing at room temperature, and if everything checks out we move on to our stress testing "heat chamber" that tops out at 50°C. Experience indicates that while many units can stand the overload testing at room temperature, others will have difficulty with the higher temperature and overload combined. Only the top units will survive this torture test.

We're going to change the order or presentation and begin with the results first, followed by pictures and discussions of the individual units. We will sort the products according to their rated output rather than name so that similar units are in close proximity to each other.

Product Comparison - Loading Charts


View All Comments

  • tynopik - Friday, November 23, 2007 - link

    the efficiency charts are fantastic as you can see exactly how all the units compare at a specified wattage

    but then you go back and do the acoustics charts by % load? why?

    if i want to see how all the units compare at a 500w load, there's no easy way to do that as that might be a 68% load on one unit and a 55% load on another unit
  • Christoph Katzer - Friday, November 23, 2007 - link

    Next time will do Reply
  • Vidmar - Saturday, November 24, 2007 - link

    Thanks for doing the charts in watts instead of load. I've been asking for that for some time. As has been said here it makes it much easier to find a good unit based upon a known wattage your system uses. Good article. Reply
  • tynopik - Friday, November 23, 2007 - link


    and then once all units are tested to the same baseline, that opens the door for dynamic comparisons

    as you build up a database of reviews, you could have a dynamic system where you can choose a 400-500 watt unit you reviewed 9 months ago and a 600 watt unit you just reviewed and it will generate the comparison charts on the fly

    something for the future perhaps ;)
  • Etern205 - Thursday, November 22, 2007 - link

    Newegg is selling the Antec TruePower Quattro 850 at $249 while
    the 1KW version is selling for $299 with a -$80 instant rebate!

    850w version">

    1KW version">
  • Traciatim - Thursday, November 22, 2007 - link

    Could you please design and test with a machine that actually uses 700+ Watts of DC output? Reply
  • Jjoshua2 - Thursday, November 22, 2007 - link

    I like the old review better. I don't have time to read the whole reviews, so I just read the conclusion and then go over a few interesting paragraphs. I hope you have a longer conclusion next time!
  • Christoph Katzer - Friday, November 23, 2007 - link

    Ehm there are 8 pages comparison/conclusion.... not enough?

    Of course people not appreciating the work and just read the last page find it boring... so next time I write a page about 10 PSUs and that'd be enough? ...
  • Googer - Thursday, November 22, 2007 - link


    You are far better off with the PC Power & Cooling Silencer 750 QUAD for a lower price and equal or better performance.

    Check the hot deals section of Anandtech forums, a little while ago I posted a $50 price drop of the Silencer 750 down to a budgetable $150.">
  • Christoph Katzer - Friday, November 23, 2007 - link

    That would be a really good deal indeed. Reply

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