Corsair RM750x PSU Review

Pros, Cons And Final Verdict

For those of you who think 140 bucks is way too much to pay for a 750 W PSU, Corsair lowered the price a bit with the RM750x, which costs $10 less. If you ask us, we would happily pay the small premium for Corsair Link compatibility and the fluid dynamic bearing fan, which will last much longer than the rifle-bearing one that the RM750x uses. Corsair would be wise to enlarge the price difference between the RM750i and the RM750x if it wants to sell more of the pricier unit. We think a price difference of $20 would be ideal, but we encourage the company to make it even larger by dropping the price of the RM750x, not by increasing the price of the RM750i. The RMx models use the same platform as the RMi units, so their performance and reliability are very good.

The RM750x unit we evaluated in this review achieved decent load regulation at +12V and quite tight regulation on all of the other rails. In addition, its efficiency readings were solid, even under very high operating temperatures, and ripple suppression was amazing throughout all of the load ranges. Another important feature of this platform is its silent operation, thanks to the passive operation at light and moderate loads, and the relaxed fan profile. This unit would be ideal for systems where silent operation is critical. However, it would have been nice if Corsair had added the option to select between normal operation and semipassive operation. A small switch could offer this capability and could also play the role of the fan-test button, which is missing in the RMx units. We believe that in PSUs that utilize a semipassive operation, there must be an option to check if the fan is working normally, meaning that it is spinning.

To wrap up, the main competitor of the RM750x is the RM750i, which, for only $10 more, offers digital monitoring capabilities, allows the control of its cooling fan and has multiple +12V rails that can be combined into one. Plus, all of those additional features are possible through the Corsair Link software. On top of that, the RM750i is equipped with an FDB fan and a fan-test button. We believe that even if you don't care about the digital interface of the RMi, the FDB fan should intrigue you.

With the current pricing scheme, the RM750x faces strong competition, but this could easily change if Corsair decides to bring down the price to $120 or less. Finally, like the RM750i, the RMx model comes with only a single EPS connector. Considering most high-end mainboards need at least one EPS connector and a four-pin ATX one, Corsair should equip these units with a couple of EPS connectors to rectify this downside.

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

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19 comments
    Your comment
  • Blueberries
    I've been promoting these for a while, it's nice to see Tom's do an article on them. The only reason these are Gold rated is because they just miss the Platinum rating at 20%.

    They have a 650x as well that's a little cheaper.
  • Amdlova
    High Rate Faliure can be the the name of this series of corsair. for Now EVGA or SEASONIC power supplies. don't spend a penny on corsair products...
  • Aris_Mp
    Please keep in mind that some Corsair PSUs are also made by Seasonic. Also this series is very new to have a high rate of failures. Unless you have some solid facts to share on the older RM line which is out for quite some time now.
  • jonnyguru
    1335368 said:
    High Rate Faliure can be the the name of this series of corsair. for Now EVGA or SEASONIC power supplies. don't spend a penny on corsair products...


    Wrong on so many levels.

    YOU do not have the failure rate for this or any other Corsair PSU.

    This PSU is the RMx, not the RM, so even if you did have a failure rate, it would only be about two weeks of data.

    If you were talking about the RM and not the RMx, and you actually had failure rate data, you would see that the failure rate on the RM wasn't really high at all.
  • PureBlackFire
    Quote:
    High Rate Faliure can be the the name of this series of corsair. for Now EVGA or SEASONIC power supplies. don't spend a penny on corsair products...


    *sigh* nonsense comment of the day.
  • chalabam
    Tomshardware:

    I don't know if this is a problem of your site, or my PC/IP, but frequently the charts do not load, even when the page "ends" loading.



    Sometimes, if I "reload", then the charts also load.

    I open all the article pages simultaneously, on different tabs, so I don't need to wait for each one to load.
  • Rookie_MIB
    The older RM units weren't 'bad' really, they were ok, but Corsair has been stepping up its game with quality parts and build on some of these newer units which is nice to see. You can never have too many solidly designed units to choose from - competition toughens the breed.
  • Blueberries
    Quote:
    High Rate Faliure can be the the name of this series of corsair. for Now EVGA or SEASONIC power supplies. don't spend a penny on corsair products...


    Did you even LOOK at the article? The only problem with these are the Sinopowers on the secondary side, and that's not even a "bad" thing. Oh and btw, some of the best power supplies in the world are Superflower OEMs produced by Corsair.
  • mavikt
    With these in depth coverage of PSU's I propose introducing a tier'ing table thing at the and of each review (or perhaps a best buy PSU of the month) equivalent to what's done for CPU's and GPU's, ranking PSU models (perhaps too the makers). I saw a comment here on toms on another PSU news flash in the comment section referring to such thing in the forum but now I can't find it.
    Permanent'ing such thing from the editorial side would be great!
  • anort3
    Quote:
    Quote:
    High Rate Faliure can be the the name of this series of corsair. for Now EVGA or SEASONIC power supplies. don't spend a penny on corsair products...
    Did you even LOOK at the article? The only problem with these are the Sinopowers on the secondary side, and that's not even a "bad" thing. Oh and btw, some of the best power supplies in the world are Superflower OEMs produced by Corsair.


    Corsair doesn't use SuperFlower anywhere in its lineup. CWT, Great Wall, Flextronics, Seasonic and Chicony which has since been dropped are all the OEMs Corsair uses or has used.
  • JackNaylorPE
    Tier lists and OEM brand are by no means an indicator of quality. Just because a certain OEM is used is no guarantee of quality. Just like Corsair sells Great, Good, moderate and crappy PSU's, most OEMs also produce a wide range of quality.

    Tier lists will include an entire product line in a category based upon a single model review. The Corsair HX 750/850 were great, the 1000 / 1050 were dogs but all were placed in the same tier. Below we see that CWT made their lowest tier as well as some of the best products Corsair ever sold.

    CS was made by Great Wall
    CX and GS by CWT
    VS by CWT
    RM 450-650 were made by CWT,
    RM 750 and 850 by Chcony
    RM 750v2 -850v2 and 1000 were made by CWT
    RMi / RMx series are made by CWT
    HX 650 was made by Seasonic
    HX 750, 850 and 1050 were made by CWT (2/3 were excellent)
    HXi series was made by CWT
    AX series was made by Seasonic
    AXi was made by Flextronics
  • Blueberries
    218893 said:
    Quote:
    Quote:
    High Rate Faliure can be the the name of this series of corsair. for Now EVGA or SEASONIC power supplies. don't spend a penny on corsair products...
    Did you even LOOK at the article? The only problem with these are the Sinopowers on the secondary side, and that's not even a "bad" thing. Oh and btw, some of the best power supplies in the world are Superflower OEMs produced by Corsair.
    Corsair doesn't use SuperFlower anywhere in its lineup. CWT, Great Wall, Flextronics, Seasonic and Chicony which has since been dropped are all the OEMs Corsair uses or has used.


    Wrong. The AXi is a SuperFlower Leadex OEM. Which is sometimes produced by Corsair, Seasonic, and EVGA.
  • anort3
    The AXi OEM is Flextronics..... Unless you know something all the review sites don't?

    http://www.realhardtechx.com/index_archivos/Page447.htm

    http://www.orionpsudb.com/corsair

    http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story6&reid=317

    http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=378


    And why would Seasonic make a SuperFlower platform? They don't. The 2 companies are direct competitors. You are correct about EVGA using SuperFlower though.
  • Blueberries
    I'll shut up now. I thought the AXi was SuperFlower which is the stem of my confusion
  • jonnyguru
    35894 said:
    The Corsair HX 750/850 were great, the 1000 / 1050 were dogs...


    They were?!?!?! Says who???
  • JackNaylorPE
    Quote:
    They were?!?!?! Says who???


    The guy who gave it a 8.5 performance * and 7.0 Build Quality rating :)
    http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=245

    The 850 got a 10 in performance but back then no BQ ratings
    http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=153

    * 1000 wasn't that bad with a 9.0 performance rating. I used it 3 times as I recall, had problems with 2..... one would hiccup under SLI loads, a user build had fan noise issues.
  • jonnyguru
    35894 said:
    Quote:
    They were?!?!?! Says who???
    The guy who gave it a 8.5 performance * and 7.0 Build Quality rating :) http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=245


    Right. And if you read the fine print:

    "More loose heatsink screws to deal with. But at least there were only two of them in there this time that could be considered a potential problem. Two points off for that. It'll probably never be a problem for 99% of these sold, but I'm an electronics tech. I get to be picky with stuff like that."

    This doesn't make a product "a dog".

    AFAIK, it really wasn't a problem for 99% of the folks out there and since it was pointed out in the reviews, CWT started using nylon washers or thread lock on all screws.
  • tacgnol06
    RM750i is currently slightly cheaper than this model on Newegg, which leads me to wonder why they'd release this version to begin with, unless they're phasing it out to replace it with something cheaper to make for around the same retail price... oh.
  • JackNaylorPE
    112719 said:
    Right. And if you read the fine print: "More loose heatsink screws to deal with. But at least there were only two of them in there this time that could be considered a potential problem. Two points off for that. It'll probably never be a problem for 99% of these sold, but I'm an electronics tech. I get to be picky with stuff like that." This doesn't make a product "a dog".


    I did read the fine print, but I am speaking "in context" ... As you said ... 2 points off... that only brings it to a 9. In the general context of things, I normally would call a 9.0 build quality rating a dog.... perfectly acceptable, perfectly suitable for an office or budget restricted gaming box.

    But when one is looking at, and prepared to pay for what the HX series bought to the table for a presumed moderate to higher end build for overclocking or gaming, the mindset is "top end".

    I expect a 10.0 here. When you are paying 10.0 quality a prices, a 9.0 BQ / Perf. rating is gonna get a "dog" label, at least in my eyes. If I wanted 9.0's, I'd look at cheaper model lines. As a TX, and without the careless assembly, the moniker would not have been used.