Corsair SF450 PSU Review

Corsair enters the SFX PSU market with its new SF series consisting of two models at 450W and 600W capacities. Both power supplies are fully modular, promise high performance and come with 92mm fans to minimize noise output.

Except for SilverStone, most companies don't seem to care much about the SFX form factor. This is changing though, as Corsair recently introduced its SFX-based SF series. There are currently only two models, hitting the 450 and 600W capacity points (we'd really like to see the company come out with something under 400W too). Both SF units are 80 PLUS Gold-certified and feature fully modular cabling to simplify installation. In addition, Corsair implements a semi-passive mode called Zero RPM, which deactivates the fan under light loads to enable silent operation. A larger 92mm fan is used to further suppress acoustic output. In comparison, most SFX power supplies employ 80mm fans that spin faster, creating more noise. Finally, Corsair is only using Japanese capacitors, assuring you get years of trouble-free use from the SF-series PSUs, which are also backed up by a seven-year warranty.

In this review, we're evaluating the lower-capacity SF450. Thanks to its couple of PCIe connectors, this PSU won't have a problem supporting a high-end graphics card, allowing you to build a capable gaming system inside a small chassis with minimal space for the power supply.

Corsair specifically calls out its larger fan's specially-shaped blades that move more air through the SF450 with less noise compared to conventional fans. Part of this could be a result of Corsair checking blade balance during its quality control phase, avoiding any problems that might result from vibration at high speeds.

Of course, noise isn't always generated by the fan. It can also come from capacitors and coils creating what we refer to as coil whine. Corsair's engineers paid extra attention to the components they used in the SF family, circumventing this issue.

Specifications

On the product's official page, Corsair states that this product is engineered to meet maximum power output at a 40 °C temperature rating. However, in the technical specifications section, it's rated at 50 °C for full load. We'll determine which is right with our tests at greater than 40 °C ambient.

Since the supply's feature set includes over-temperature protection, we have nothing to worry about in case the thermals inside go sky-high. The PSU should shut down automatically to cool itself off.

We'd like the option to disable the SF450's semi-passive mode, though we do appreciate a long seven-year warranty. We can't help but wonder however why these PSUs weren't include in the recent warranty upgrade that Corsair provided to the AXi, HXi, RM and RMx lines (from seven years to ten years).

Power Specifications

Rail3.3V5V12V5VSB-12V
Max. PowerAmps152037.52.50.3
Watts10045012.53.6
Total Max. Power (W)450

The 5V rail can deliver more amperage than the 3.3V rail, though this won't matter in a contemporary system drawing most of its current from the +12V rail. There is a single +12V rail and it can deliver the PSU's full power alone (typical for a PSU equipped with DC-DC converters for generating the minor rails). Finally, the 5VSB rail has the typical capacity for a modern, low/mid-wattage PSU.

Cables And Connectors

Modular Cables
DescriptionCable CountConnector Count (Total)
ATX connector 20+4 pin (310mm)11
4+4 pin EPS12V (400mm)11
6+2 pin PCIe (400mm)22
SATA (100mm+115mm+115mm+115mm)14
Four-pin Molex (100mm+115mm+115mm+115mm)14

All cables are flat and stealth. On top of that, they're pretty short since, most likely, the SF450 will be installed in small cases. Nevertheless, we think the main ATX cable is too short; it should at least be 35cm long.

A big asset of this PSU is the fact that it is equipped with two PCIe connectors on dedicated cables. Given that 450W is more than enough to feed a flagship graphics card and potent CPU, just one PCIe connector would have crippled this unit's usability.

Of course, we couldn't expect this PSU to have two EPS connectors, and the number of peripheral connectors is satisfactory. On the other hand, it would be nice to get a couple more SATA connectors, bringing the total to six, and we wonder why Corsair didn't offer a Berg (FDD) adapter. Most enthusiasts probably wouldn't use it, but a bundled adapter could have come in useful. Finally, all connectors use standard 18-gauge wires, which are recommended by the ATX spec.

Power Distribution

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

MORE: Best Power Supplies
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MORE: How We Test Power Supplies
MORE: All Power Supply Content

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  • joz
    "No berg connector," is a con? And this is why Johnnyguru is the better website.
  • spdragoo
    Interesting...a small-factor PSU with enough power & PCIe connectors for those with a prebuilt system that want to upgrade their GPUs without having to rebuild the entire system from scratch.
  • turkey3_scratch
    Anonymous said:
    "No berg connector," is a con? And this is why Johnnyguru is the better website.


    I find it hard to believe you actually read power supply reviews, because on Jonnyguru OklahomaWolf always scores against having a berg connector. Also, Jonnyguru only tests a few things compared to Aris's reviews on Tomshardware and Techpowerup.

    Edit: I just realize I misinterpreted what you said. I do apologize, it was my mistake. I did not realize the word "not". Yes, Aris and Jonnyguru have different reviews on berg connectors. I still don't think that just because a berg connector is a good thing means that Jonnyguru is a better review site. That seems to be an extremely minor detail to judge one whole review site to this one.
  • Onus
    Hmmm, looks like the only thing not to like is that all the SATA connectors are on one cable, which could be a problem even in some small cases where this would be used; the optical drive might not be near the other drives.
  • jimmysmitty
    Anonymous said:
    Hmmm, looks like the only thing not to like is that all the SATA connectors are on one cable, which could be a problem even in some small cases where this would be used; the optical drive might not be near the other drives.


    And that is easy to solve since you will probably be able to buy cables and change the molex out for another SATA cable, like all Corsair PSUs.

    I wish this was out when I rebuilt my HTPC. Would have preferred it since what was available at the time was just meh and nowhere near the performance.
  • turkey3_scratch
    Just finished review. Great unit, wonderful. I'd take this over one of the Silverstones any day.
  • Aris_Mp
    Quote:
    "No berg connector," is a con? And this is why Johnnyguru is the better website.


    Some components still need a berg connector ( e.g. sound card panels, fan controllers, etc.) And it costs almost nothing to add a berg adapter into the bundle.
  • JQB45
    Exciting to see more SFF power supplies of good quality. Now I have even less reason not to buy a mini-itx case next time.
  • turkey3_scratch
    Anonymous said:
    "No berg connector," is a con? And this is why Johnnyguru is the better website.


    On second read of your post, I misinterpreted what you said, and I do apologize. I thought you were upset that including a berg connector was a con, I'm sorry I misinterpreted it. Yeah, this unit doesn't have a berg connector. Here's the thing: you have OklahomaWolf who scores against having berg connectors, and you have Aris who likes to see berg connectors. Two complete opposite subjective standpoints. What I don't understand is how this makes Jonnyguru a better site.

    Whenever I read power supply reviews, I always ignore the conclusion page. I usually don't read it. The information is all there for you to judge. Whether or not the author thinks a berg connector is good or bad is an opinion, but it does not detract from how professional Aris's reviews are. I mean, come on, Jonnyguru does not test transient response, hold-up time, AC_LOSS to PWR_OK, 1500 crossload possibilities, extensive efficiency and fan RPM, etc. tests. I just can't see how Jonnyguru can be a better review site because they only do a fractional amount of testing.

    Jonnyguru's resources are limited, so it's understandable. I think some people like Jonnyguru just because of how "fast" one can fly through the reviews. It takes me a solid 25 minutes of thorough analysis to read Aris's reviews, I can go through a Jonnyguru one in under 10 minutes. There is just so much information here, so why is it you think Jonnyguru is a better site?
  • AlistairAB
    Thank you Tom's Hardware for highlighting the lack of the SFX adapter bracket. It can be purchased directly from Corsair at the following link:

    http://www.corsair.com/en-us/sfx-to-atx-psu-adapter-bracket

    This was also mentioned in a newegg.ca review, and received many down votes. Perhaps this is because of American focused reviews, so most people think it is not a big deal to order a $5.99 adapter directly from Corsair or through a 3rd party.

    However this is actually a serious mistake, as ordering this to Canada from Corsair requires over $50 USD in shipping. Total cost for the bracket after shipping and taxes is over $80 CAD which is absolutely ridiculous for a part with no retail availability or alternatives that should have been included in the box.

    I talked with Corsair support this morning and opened a ticket, and they provided exemplary customer service and have now promised to send the adapter to me in Canada for free. Perhaps this will work for some of you having the same problem.

    There are many small form factor cases that accept ATX PSUs that need this bracket (Silverstone and Lian Li cases), where the short cable lengths don't pose a problem.
  • jonnyguru
    Quote:
    Thank you Tom's Hardware for highlighting the lack of the SFX adapter bracket. It can be purchased directly from Corsair at the following link:

    http://www.corsair.com/en-us/sfx-to-atx-psu-adapter-bracket

    This was also mentioned in a newegg.ca review, and received many down votes. Perhaps this is because of American focused reviews, so most people think it is not a big deal to order a $5.99 adapter directly from Corsair or through a 3rd party.

    However this is actually a serious mistake, as ordering this to Canada from Corsair requires over $50 USD in shipping. Total cost for the bracket after shipping and taxes is over $80 CAD which is absolutely ridiculous for a part with no retail availability or alternatives that should have been included in the box.

    I talked with Corsair support this morning and opened a ticket, and they provided exemplary customer service and have no promised to send the adapter to me in Canada for free. Perhaps this will work for some of you having the same problem.

    There are many small form factor cases that accept ATX PSUs that need this bracket (Silverstone and Lian Li cases), where the short cable lengths don't pose a problem.


    True. Shipping costs from Corsair.com can be quite high. But an SFX to ATX bracket is not a proprietary item or anything of the sort. You can buy them from several outlets from $5 to $7 and often with free shipping.
  • turkey3_scratch
    If you're purchasing an ITX machine that takes an ATX PSU, I see no reason to purchase an SFX unit personally. I guess if you "upgrade" to an ATX PS2 type of case, then you may be in trouble with not having the adapter. But part of the premium costs this unit has is simply because it is the SFX form factor which has little competition. In an ATX case, there are cheaper 450W ATX units that'll perform the same.
  • AlistairAB
    Quote:
    True. Shipping costs from Corsair.com can be quite high. But an SFX to ATX bracket is not a proprietary item or anything of the sort. You can buy them from several outlets from $5 to $7 and often with free shipping.


    Sorry, maybe my post wasn't clear about the fact that you can't order one in Canada easily from anyone. So you'd be stuck with the Corsair one at over $80. I just did a quick search of the major retailers (ncix, newegg, etc.) and none of them sell an adapter in Canada, that I can see. In fact I haven't yet found a generic one from any store.

    Quote:
    In an ATX case, there are cheaper 450W ATX units that'll perform the same.


    That's just it, there aren't any ATX units that will perform the same in terms of noise etc., that are actually ATX in size (the official 140mm, required for many small cases). All Corsair gold PSUs with silent operation are 160mm or longer. EVGA has the GS series at 150mm long. I purchased a Silverstone one, but it made weird noises at sparse intervals (rising tones, fan crunching etc.). Also only the Corsair model actually works right, and keeps its fan off at low temperatures. The EVGA and the Silverstone both turn on at idle even though my case is only 35 degrees, with the video card off. It's a kind of pseudo-silent mode for marketing purposes that doesn't actually work most of the time.

    This SFX PSU from Corsair is vastly superior in quality and has a functioning silent mode. Read the Tom's Hardware review to see how superior it is. With it I'll be able to add and remove video cards and SSDs in my Lian Li mini case, without having to spend an hour tidying up afterwards. (Just because a case supports 150mm or smaller, doesn't mean it will be easy to use it. The SFX one will be a breeze to use).

    (quick note: typo earlier, Corsair have now promised...)
  • nukemaster
    Great review.

    If my FSP 300 dies at least I have an extra option. The fan would never run at idle :)
  • powernod
    Anonymous said:
    "No berg connector," is a con? And this is why Johnnyguru is the better website.


    1)If you don't need it you can throw it away!!
    2)On the other hand, whoever needs a berg connector, and the package doesn't include one, then he/she must spend extra time to buy one.
    Which one of the 2 solutions do you think it's better for the customer? ;)
  • Andi lim
    I must agree with turkey3_scratch, that Aris_Mp reviews much more informative and detail compare to jonnyguru. The only lack of Aris_Mp review i can find, that the review lack of joke .
    Btw, the APFC boost diode is 4A 600V, not 6A ( CREE C3D04060A )
  • bettsar
    I was looking at this as a replacement for a noisy industrial SFX supply, and a discrepancy came up in the dimensions. It looks like the exterior side (back) of the power supply is 63.5x125mm. The SFX standard has more than one size configuration. The supply I'm replacing has an exterior dimension of 70x100mm. Make sure you're looking at the right power supply for your case.
  • Aris_Mp
    The SFX dimensions according to Intel's SFX12V guidelines are 125x63.5x100mm (WxHxD). Anything with larger or smaller dimensions either belongs to another form factor or it isn't SFX compatible.
  • bettsar
    Quote:
    The SFX dimensions according to Intel's SFX12V guidelines are 125x63.5x100mm (WxHxD). Anything with larger or smaller dimensions either belongs to another form factor or it isn't SFX compatible.



    The standard SFX power supply dimensions are defined in Appendix D of the SFX12V Power Supply Design Guide. It's dimensions are 100x63.5x125mm (WxHxD).

    There are other variants specified in the other appendices. The Corsair supply in this article conforms to Appendix C, which calls out 125x63.5x100mm (WxHxD). A quick search of Newegg shows that the majority of supplies are designed to the Appendix C dimensions.
  • Aris_Mp
    Indeed this is the reduced depth SFX (SFX12V V3.3 guidelines) where the SF450 belongs. In the other ones the Width and the Depth are just the other way around. All SilverStone SFX units have the same dimensions as well.