Corsair RM750i Power Supply Review

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Corsair is revamping its RM line, adding the letter "i" to highlight a more advanced digital interface — today we check out the RM750i.

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Pros, Cons And Final Verdict

Corsair made a huge update to its still-active RM line with the new RMi PSUs, which offer great performance improvements, including an even lower noise output. We are pretty sure that the company had a very hard time achieving lower noise output than with the RM units, which are still among the most silent PSUs money can buy. The new RMi units are even competing with Corsair's own HXi line, since they are very close performance-wise and only slightly less efficient. Actually, the main difference between the RMi and the HXi PSUs (both are based on the same platform) is the efficiency certification. Considering the small gap between Gold and Platinum efficiency, we believe that the RMi PSUs will be the preferred choice for most users.

The RM750i that we evaluated today registered decent load regulation at +12V and excellent load regulation on the rest of the rails. In addition, the PSU managed to offer a significant efficiency boost at light loads compared to the older RM750 unit, while with normal loads, it stayed very close to the competition. In ripple suppression, the CWT platform is an excellent performer, and one of the key features of this PSU is the silent operation even under extremely tough conditions.

Corsair's RM line included some of the most silent PSUs available, and our noise measurements show that the new RMi units managed to take the lead even in this section. In addition, the exclusive use of Japanese capacitors, the improved digital interface that offers enhance functionality, the longer warranty period and the significant performance boost make the RMi a much better option not only compared to the older RM units, but also to comparable PSUs from other manufacturers.

It is clear that Corsair wants to dominate the PSU market, and with PSUs like the new RMi, the company is on the right path to achieve this goal. Currently, the RM750i's only direct competitor is the EVGA SuperNOVA G2 750 W, which uses the excellent Super Flower Leadex Gold platform, costs less and has an even longer warranty. However, there is a catch: The EVGA offering isn't equipped with a digital interface, and more important, it loses to the RM750i in the noise output section.

The only unit capable of facing the RM750i in both performance and noise output is the new Seasonic Snow Silent-750. However, that unit belongs to a higher category and thus costs much more. On top of that, the Snow Silent-750 doesn't offer any digital goodies. The only serious omission in the RM750i PSU is the lack of a second EPS connector, and this can cause headaches for users who want to use it along with a high-end mainboard that has a four-pin ATX12V in addition to the standard EPS socket. Users can use a Molex adapter for this, but we've found that this is not a safe option. A high-end 750 W PSU like this one should have two EPS connectors, as is the case for the HX750i unit.

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

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Aris Mpitziopoulos
Aris Mpitziopoulos
Contributing Editor

Aris Mpitziopoulos is a contributing editor at Tom's Hardware, covering PSUs.

18 Comments Comment from the forums
  • JQB45
    Nice to see quality improving some.
    Reply
  • Luay
    Aris

    Thanks for the thorough review.

    The RM750i does beat the G2 750 at $10 more, which is a good trade for a mpore quite operation, and is $20 cheaper than the Snow Silent 750, but how does it compare to the $10 more expensive P2 750?
    Reply
  • Aris_Mp
    I am sorry but I haven't reviewed the P2 750 model yet. However since it is Platinum it should be compared with the HX750i.
    Reply
  • jonnyguru
    Unless efficiency isn't that important to you.
    Reply
  • Luay
    No I'm comparing it based on price.

    Since the gold rated RM750i and the platinum P2 750 are $10 apart, excluding the rebate, and as Jonny (The Jonny??) said, a few %s of efficiency isn't as important to me as something as tangible as emitting noise.
    Reply
  • Dan414
    This seems like the droids/PSU I've been looking for. That or maybe the 850i. Also, I like the white lettering - that way it will match my case no matter what lighting I have inside.
    Reply
  • synphul
    I'm confused, there's no other product that compares to the corsair rm750i except the evga g2 750 and the seasonic snow silent 750 which is a higher category and price. Yet isn't that the ss-750km3 sitting at $10 cheaper?

    Cwt may be improving but it's not ss quality. Hard to face the two off when they're so close in price or the seasonic is cheaper. I fail to see how it's a better option than the competition. A better option than their own lineup maybe, but that's not saying a ton.

    I suppose it's true it comes with corsair link, though with psu's already this quiet not sure the need is there to control the fan beyond active variable control built in and silent mode at low draw. I've never needed to monitor my psu temp or control the fan speed even on a plain old active fan design. Comes off as a bit gimmicky to try and create added value. Don't get me wrong, this would be nice on an otherwise loud psu with no fan control and no silent operation mode at all but in the face of being quiet and having variable/silent fan operation it's a little redundant.

    Idk, like I said it's nice to see they're trying to improve quality in some areas but they don't even come in under the competition. As of right now they're more expensive than the competition. Personally I'll stick with seasonic.
    Reply
  • trifler
    If any PSU companies read this, I want to see molex discontinued, at least on the non-modular power supplies. At least offer some power supplies that don't have molex.
    Reply
  • fil1p
    It's good to see that all the caps a Japanese on this one. I like Corsair PSUs, but the last gen RM series had some lower quality caps in there, which quite frankly shouldn't have been in an enthusiast PSU at that price point in the first place.
    Reply
  • jonnyguru
    16336613 said:
    Cwt may be improving but it's not ss quality.

    How do you know? ;-)

    16336613 said:
    I suppose it's true it comes with corsair link, though with psu's already this quiet not sure the need is there to control the fan beyond active variable control built in and silent mode at low draw. I've never needed to monitor my psu temp or control the fan speed even on a plain old active fan design.

    You can also monitor voltages and load and calculate efficiency. So it does a lot more than what you're stating.
    Reply