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Corsair RM550x Power Supply Review

The lowest-capacity unit Corsair's RMx line outputs up to 550W and is 80 PLUS Gold-certified. It features fully modular cabling, offers great performance and is nearly silent throughout its operating range, too.

Pros, Cons And Final Verdict

CWT, under Corsair's guidance, manufactures several excellent PSU families, including the RMi and RMx. The only differences between them is the lack of a digital interface and a rifle bearing fan in the RMx models, which push their prices down. Indeed, many enthusiasts don't care about the RMi's digital goodies, preferring simpler (and less expensive) alternatives. I personally believe that the ability to monitor a PSU's operation and control its fan is important. But I also understand that not everyone shares my opinion.

Regardless, the RMi line-up doesn't even include a 550W member, so the RM550x stands alone in Corsair's portfolio. The competition is pretty compelling; EVGA's 550 G2 is probably the most noteworthy opponent. Compared to that power supply, the RM550x features even better performance and quieter operation. In fact, Corsair's offering more closely resembles a passive PSU than a normal one. Its semi-passive operation lasts for a long time, and even when the fan engages, it spins slowly. We had to push the PSU very hard to get its fan to register more than 30 dB(A). Normally we would be a little skeptical about the reliability of a PSU without heat sinks on its secondary side and such an unobtrusive fan. However, Corsair appears to be very confident in CWT's design. Otherwise it wouldn't equip the RM550x with a seven-year warranty. 

The RM550x is an amazing PSU with fantastic ripple suppression, tight load regulation on the minor rails and excellent performance with transient loads. The cherry on top is nearly silent operation. On top of that, this unit is highly efficient, although some other Gold-rated PSUs with similar capacity fare a bit better. Another advantage of the RM550x is the quality of its internal components. The only thing that we would like to see in this PSU is a convenient way to test the fan's proper operation. The fan does spin for a short time every time the power supply is switched on, but we'd like Corsair to add a fan test button like the one on its RMi units.

In general, it is really hard to find any flaws in a PSU like this. We're extra-picky though, so we would like to see even tighter load regulation on the +12V rail. Finally, it would be nice if Corsair dropped its price closer to 90 bucks. That'd increase the RM550x's performance per dollar ratio, bringing its value more in line with EVGA's 550 G2, which previously dominated the mid-wattage category alongside the 650 G2.

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

Follow us on Twitter @tomshardware, on Facebook and on Google+.

  • Dark Lord of Tech
    I just wish they would get the price down , these are a great lineup \ RX.
    Reply
  • basroil
    From the performance it seems like CWT is finally something to consider... It's showing Leadex Gold/Seasonic levels of performance.
    Reply
  • Dark Lord of Tech
    I love the RMX and RMI series , price just keeps me away from the purchase , very very solid.

    Knock a little off the price and these would fly out of warehouses.
    Reply
  • William Henrickson
    They were on sale when new. I snagged an RM750i for $105 -w- shipping
    Reply
  • Dark Lord of Tech
    Yeah the 550w should be about 79.99 to 89.99 , no rebates.
    Then I would grab a few.
    Reply
  • JQB45
    Yeah the 550w should be about 79.99 to 89.99 , no rebates.
    Then I would grab a few.

    Corsair RMx 550W 80+ Gold Certified Fully-Modular ATX Power Supply
    http://pcpartpicker.com/part/corsair-power-supply-cp9020090na$79.99

    $89.99 for the 650W version.

    UPDATE:

    Sorry thats with mail in rebates...
    Reply
  • Dark Lord of Tech
    I don't do rebates , takes to long , and maybe you get it maybe you don't , I'll wait for a newegg drop.
    Reply
  • Nintendork
    We really need more platinum/titanium PSU's at 300-500w. Most PC's stays near idle and with the efficiency focused gpu's/cpu's they rarely exceed 100w unless you tax them.
    Reply
  • turkey3_scratch
    Plus companies often don't even send you the rebates, sometimes they just say it was too late or some other bull crap like that. I agree with Blackbird. I've been waiting for a review of the 550 RMx, and what I get out of this review is that it trades blows with the 550 G2 that saying one or the other is better is just silly and extremely nit-picky. They are both incredible. Both offer a 7 year warranty, as only higher-wattage G2s offer the 10 year warranty. They are just so close, that when it comes to picking the better one, the cheaper one is better, and the G2 is cheaper.

    I've actually quit including rebates in my pcpartpicker lists. They are a pain and I don't think they reflect the true cost of an item.
    Reply
  • turkey3_scratch
    17653281 said:
    We really need more platinum/titanium PSU's at 300-500w. Most PC's stays near idle and with the efficiency focused gpu's/cpu's they rarely exceed 100w unless you tax them.

    I wish so, but unfortunately if this were to happen they would end up priced the same as any Platinnum/Titanium 650W unit. It's just the way it works. Quality low-wattage models are priced almost the same as the higher-wattage models. I would like to see something like a Titanium 250W model come out from Seasonic. Something like $40, fully modular. Will never happen, though.
    Reply