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Corsair CS850M 850W Power Supply Review

Decent Performance; Tough Competition

The folks at Corsair know that the big money in PSUs is made from the mid-range space. So, they added a more powerful supply to the company's CS family offering up to 850W of output. That's enough to drive an enthusiast configuration with a couple of graphics cards. Nowadays, most builders keep their PSU budgets low, meaning manufacturers need affordable options in their portfolios.

The CS850M we evaluated today costs a little more than $100 dollars, so we can’t exactly call it cheap. However, that price is in line with most of Corsair's competition. For the time being, it is difficult for any company to offer 80 PLUS Gold efficiency and a semi-modular cabling with capacity approaching 1000W, and still hit a price point around $100 without seriously compromising quality.

But because of the many PSUs in this segment, Corsair needs to drop its price even more to make this specific model a stand-out. At $120, the CS850M approaches what you'd pay for much higher-end power supplies that offer better performance and longer warranty coverage.

The CS850M registers decent overall performance; it would have been much better if the platform handled transient loads more deftly. In the real world, a PC won’t subject its PSU to steady loads. Rather, levels will vary constantly according to utilization. Admittedly, our Advanced Transient Load benchmarks are based on some extreme case scenarios, but any modern PSU should be able to handle them. The CS850M managed to pass those tests successfully, but we'd like to see lower deviations on its rail, which would lead to better performance.

Our efficiency testing went much better; the CS850M yielded satisfactory load regulation results, too.

Ripple suppression on the +12V rail could be improved. Although it was excellent on the other rails, the +12V rail's performance is what matters since most PC components are powered by it. Our advice to Corsair is to sell the CS850M at a lower price, creating a larger price gap between higher-end PSUs with similar capacity.

Aris Mpitziopoulos is a Contributing Editor for Tom's Hardware, covering Power Supplies.

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  • codygriffy
    Looks very nice!
    Reply
  • Shneiky
    Another CS PSU with bad caps and short life. And at 120 USD or more than 120 EUR as it appears in my district, this PSU does not stand a chance against the competition. Still a lot of people will buy it just because it has a Corsair name on it. I feel kinda bad that Corsair ruins their legacy of quality with products like CS and VS.
    Reply
  • giantbucket
    15746324 said:
    Another CS PSU with bad caps and short life. And at 120 USD or more than 120 EUR as it appears in my district, this PSU does not stand a chance against the competition. Still a lot of people will buy it just because it has a Corsair name on it. I feel kinda bad that Corsair ruins their legacy of quality with products like CS and VS.

    and then there are people who are going to hate on it just because it has a Corsair name on it...
    Reply
  • ykki
    Nice review! Can Tom's start a psu rating system (on a scale of 1 to 10)?
    Reply
  • Amdlova
    this perform really bad
    Reply
  • endeavour37a
    ykki, here is a tier list of PSUs, perhaps this is what your talking about.......
    http://www.tomshardware.com/forum/id-1804779/power-supply-unit-tier-list.html
    Reply
  • Sakkura
    Breaks ATX spec, high-ish 12V ripple, bad capacitors... No thanks.
    Reply
  • Shneiky
    ykki,

    I do not hate Corsair products because they are Corsair. I have a Corsair K70 and I love it. What I hate is cheaply made equipment that wants a price premium because it is X brand.
    Reply
  • Aris_Mp
    @ykki The relative performance graph can play this role and with much more accuracy. However it measures pure performance and doesn't take into account other factors as output noise, warranty period etc. For these factors a final rating is needed, indeed.
    Reply
  • damric
    Good review, Aris.

    I see no reason to buy this PSU when there are other good units with lower price built with better components. Example: Many XFX (Seasonic) and Golden Green (Capstone/B2) cost less but are more reliable with all good caps. Unfortunately, most consumers will be suckered in by the Corsair sticker.

    On the bright side, these Great Wall units have far less problems than the CX series. Probably even more reliable than the RM.
    Reply