Corsair RM750x PSU Review

Corsair released its RMx PSU line, which the company claims will offer good performance along with silent operation. Unlike the RMi models, the RMx units lack a digital interface, a fan test button, and uses a Rifle bearing fan instead of an FDB version.

In a sudden move, Corsair recently released another PSU series with 80 PLUS Gold efficiency. The RMx models come in five versions with capacities ranging from 550 W to 1000 W. In short, these PSUs are a budget version of the RMi models, designed for users who want high performance without paying the extra cost of a digital circuit. Since the RMx units are based on the same platform that equips the RMi PSUs, they offer good performance along with silent operation. In order to achieve high reliability in these PSUs, Corsair made no compromises in build quality; only Japanese capacitors were used, which last longer than Taiwanese and Chinese versions, and most importantly, they age much slower.


The main differences between the more expensive RMi models and the RMx versions are seen in the latters' lack of a digital interface board and fan test button (which can come very handy on a semipassive PSU). Additionally, the RMx models use a different fan, with a Rifle bearing, which is of lower quality than what the RMi models use. These use fans with fluid dynamic bearing (FDB), which is considered the best bearing available today. Another significant difference is the single +12V rail that the RMx units feature. In the RMi PSUs, the user can choose between single and multi +12V modes through the Corsair Link software.

The following table provides comparisons among the RM, RMi and RMx units.

 RMRMxRMi
80 Plus certificationGoldGoldGold
Cable systemFully ModularFully ModularFully Modular
CapacitorsJapanese Primary (APFC)100% Japanese100% Japanese
Max Cont. Output Rating40°C50°C50°C
Fan135mm Rifle Bearing135mm Rifle Bearing140mm FDB
Corsair Link SupportBasic: Monitor fan & +12V loadNoneFull
Wattage Range650, 750, 850, 1000550, 650, 750, 850, 1000550, 650, 750, 850, 1000
Warranty (Years)577
MSRPRM650 - $129.99
RM750 - $139.99
RM850 - $159.99
RM1000 - $189.99
RM550x - $109.99
RM650x - $119.99
RM750x - $129.99
RM850x - $149.99
RM1000x - $179.99
RM650i - $139.99
RM750i - $149.99
RM850i - $169.99
RM1000i - $199.99
 

Specifications

The PSU features Gold efficiency, and it can deliver its full power continuously at up to 50 degrees Celsius, like every well-performing PSU should. On top of that, it is Haswell-ready, meaning that it employs independent regulation circuits for the minor rails, and in this case, two DC-DC converters are used. In the section on protection features, we see all of them, since Corsair wanted to provide increased reliability and safety on this platform.

As we already stated, contrary to the more expensive RM750i model, this unit comes with a Rifle bearing fan. Although it is no match for an FDB, it will still get the job done, and it offers good enough reliability. Rifle bearing fans are basically an enhanced version of the plain sleeve bearing ones, offering significantly longer lifetimes, comparable to the lifetimes of ball-bearing fans.

To lower noise output at light and mid loads Corsair included a semi-passive mode, which will also increase the fan's lifetime. Finally, this unit is on the large side, at 18-centimeters long, while its price looks decent given its features.

Power Specifications

Rail

3.3V

5V

12V

5VSB

-12V

Max. Power

Amps

25

25

62.5

3

0.8

Watts

150

750

15

9.6

Total Max. Power (W)

750

There is a single +12V rail, which can deliver enough amperes to support a couple of high-end VGAs. The minor rails are very strong as well, while the 5VSB rail is a little stronger than the average, with 3A max-current output.

Cables & Connectors

Modular Cables
Description
Cable CountConnector Count (Total)
ATX connector 20+4 pin (610mm)11
4+4 pin EPS12V (650mm)11
6+2 pin PCIe (600mm+150mm)24
SATA (400mm+100mm+100mm+100mm)14
SATA (550mm+100mm+100mm+100mm)14
Four-pin Molex (450mm+100mm+100mm)13
Four-pin Molex (450mm+100mm+100mm+100mm)14
FDD Adapter (+100mm)22

A very interesting feature of the RMx units comes in the modular cables they use, which are similar to those of the RMi models and which Corsair describes as Type 4 cables. Polymer capacitors are installed on the +12V, 5V and 3.3V wires of the ATX cable and on the +12V wires of the EPS and PCIe cables, providing extra ripple filtering. On top of that, the ATX cable plugs into the PSU's modular interface through 28 pins instead of the usual 24 pins, with the extra four pins acting as sense wires. The use of sense wires allows for a very tight load regulation, Corsair claims, which is a key performance feature for any high-end PSU.

Power Distribution

Since this PSU features only a single +12V rail, we do not have anything to say about its power distribution.

MORE: PSUs 101: A Detailed Look Into 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.