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Load Regulation, Hold-Up Time And Inrush Current

To learn more about our PSU tests and methodology, please check out How We Test Power Supply Units.

Corsair SF450

SilverStone ST45SF-G

Silverstone SX500-GL

Primary Rails And 5VSB Load Regulation

Load Regulation testing is detailed here.

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Hold-Up Time

Our hold-up time tests are described in detail here.

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The hold-up time is pretty long, while the power-good signal drops before the rails go out of spec (as it should). Everything is fine here, and obviously the 390uF bulk cap is more than enough for this PSU's needs.

Inrush Current

For details on our inrush current testing, please click here.

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The inrush current is low with 115V and close to normal levels with 230V input.

Load Regulation And Efficiency Measurements

The first set of tests reveals the stability of the voltage rails and the PSU's efficiency. The applied load equals (approximately) 10 to 110 percent of the maximum load the supply can handle, in increments of 10 percentage points.

We conducted two additional tests. During the first, we stressed the two minor rails (5V and 3.3V) with a high load, while the load at +12V was only 0.10A. This test reveals whether a PSU is Haswell-ready or not. In the second test, we determined the maximum load the +12V rail could handle with minimal load on the minor rails.

Swipe to scroll horizontally

Test #	12V	5V	3.3V	5VSB	DC/AC (Watts)	Efficiency	Fan Speed (RPM)	Noise (dB[A])	Temps (In/Out)	PF/AC Volts
1	1.923A	1.994A	1.972A	0.991A	44.78	80.41%	1000	19.9	37.97 °C	0.965
12.061V	5.019V	3.343V	5.030V	55.69	46.36 °C	115.1V
2	4.887A	2.990A	2.964A	1.191A	89.76	86.90%	1000	19.9	39.22 °C	0.983
12.053V	5.013V	3.336V	5.024V	103.29	48.07 °C	115.0V
3	8.202A	3.497A	3.479A	1.395A	134.89	89.24%	1120	20.9	39.49 °C	0.982
12.045V	5.007V	3.331V	5.017V	151.16	48.64 °C	115.0V
4	11.512A	3.995A	3.967A	1.596A	179.76	90.18%	1470	26.6	41.13 °C	0.981
12.039V	5.002V	3.324V	5.010V	199.34	50.54 °C	115.0V
5	14.483A	4.998A	4.972A	1.795A	224.72	90.59%	1725	28.3	41.94 °C	0.984
12.034V	4.993V	3.318V	5.003V	248.07	51.50 °C	115.0V
6	17.452A	6.014A	5.978A	2.000A	269.73	90.42%	2100	35.0	42.64 °C	0.987
12.031V	4.987V	3.310V	4.995V	298.32	52.40 °C	115.0V
7	20.427A	7.023A	6.991A	2.200A	314.69	90.33%	2400	40.0	42.82 °C	0.989
12.026V	4.979V	3.303V	4.989V	348.37	52.91 °C	115.0V
8	23.408A	8.044A	8.006A	2.405A	359.73	90.02%	2775	41.3	43.92 °C	0.991
12.020V	4.972V	3.296V	4.983V	399.61	54.34 °C	115.0V
9	26.811A	8.555A	8.534A	2.410A	404.77	89.71%	3180	45.5	44.17 °C	0.992
12.017V	4.967V	3.292V	4.978V	451.19	55.25 °C	115.0V
10	30.168A	9.072A	9.035A	2.510A	449.61	89.34%	3450	45.1	44.30 °C	0.993
12.013V	4.962V	3.287V	4.974V	503.24	56.27 °C	115.0V
11	33.926A	9.073A	9.043A	2.512A	494.55	89.05%	3675	45.2	44.84 °C	0.994
12.008V	4.958V	3.284V	4.970V	555.39	57.74 °C	115.0V
CL1	0.102A	12.009A	12.005A	0.004A	100.82	84.15%	2370	37.8	43.70 °C	0.985
12.056V	4.983V	3.309V	5.031V	119.81	51.55 °C	115.1V
CL2	37.481A	1.003A	1.003A	1.001A	463.56	90.23%	3345	45.0	44.07 °C	0.993
12.012V	4.986V	3.314V	5.008V	513.74	55.61 °C	115.0V

Load regulation is very tight on the +12V rail. It's good on the others as well, with 5V and 5VSB achieving 1.21% and 1.41% respectively, and the 3.3V rail a little higher with 1.76% deviation. In addition, the SF450 easily meets the 80 PLUS Gold requirements at 50% output and full load. It's only 0.1% off in the 20% load test, though we benchmark in a much hotter ambient environment than the 80 PLUS organization. It's common knowledge that a PSU's efficiency is significantly affected by high operating temperatures, and this accounts for the difference.

Up to the 50% load test, the fan's noise stays below 30 dB(A). Again, we had to push the small PSU hard to make its fan spin fast enough to exceed 40 dB(A). Under normal conditions, the fan profile is relaxed so you won't have to worry about excess noise. On the next page, you will find a graph that illustrates the fan's noise under normal conditions.

Current page: Load Regulation, Hold-Up Time And Inrush Current

Prev Page A Look Inside And Component Analysis Next Page Efficiency, Temperature And Noise

Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.

33 Comments Comment from the forums

joz

"No berg connector," is a con? And this is why Johnnyguru is the better website.

Reply
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.
Reply
turkey3_scratch

17801331 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.
Reply
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.
Reply
jimmysmitty

17801372 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.
Reply
turkey3_scratch

Just finished review. Great unit, wonderful. I'd take this over one of the Silverstones any day.
Reply
Aris_Mp

"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.

Reply
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.
Reply
turkey3_scratch

17801331 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?
Reply
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.
Reply

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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.

Load Regulation, Hold-Up Time And Inrush Current

Primary Rails And 5VSB Load Regulation

Hold-Up Time

Inrush Current

Load Regulation And Efficiency Measurements