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Load Regulation, Hold-Up Time & Inrush Current

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

Corsair HX1200

Cooler Master - MasterWatt Maker 1200

SilverStone ST1200-PT

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 we measured is very long, exceeding the ATX spec's requirements by far. Corsair's power-good signal is also accurate, since it drops before the rails go out of spec.

Inrush Current

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

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We observed low inrush current levels, especially with 115V input. That's excellent, given the HX1200's high capacity.

Load Regulation And Efficiency Measurements

The first set of tests reveals the stability of the voltage rails and the HX1200's efficiency. The applied load equals (approximately) 10 to 110 percent of the PSU's maximum load 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 0.1A. This test reveals whether a PSU is compatible with Intel's C6/C7 sleep states or not. In the second test, we determined the maximum load the +12V rail could handle with minimal load on the minor rails.

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Test #	12V	5V	3.3V	5VSB	DC/AC (Watts)	Efficiency	Fan Speed	Fan Noise	Temps (In/Out)	PF/AC Volts
1	8.072A	1.986A	1.985A	0.996A	119.782	88.561%	0 RPM	<6.0 dB(A)	49.84°C	0.985
12.166V	5.032V	3.318V	5.018V	135.253	40.48°C	115.12V
2	17.182A	2.976A	2.981A	1.196A	239.633	91.874%	0 RPM	<6.0 dB(A)	51.02°C	0.994
12.151V	5.032V	3.316V	5.012V	260.827	41.46°C	115.12V
3	26.674A	3.480A	3.496A	1.395A	359.827	92.470%	0 RPM	<6.0 dB(A)	52.21°C	0.996
12.138V	5.026V	3.314V	5.005V	389.129	42.28°C	115.12V
4	36.162A	3.982A	3.979A	1.600A	479.630	92.571%	0 RPM	<6.0 dB(A)	53.55°C	0.998
12.124V	5.027V	3.314V	4.998V	518.119	43.45°C	115.13V
5	45.348A	4.979A	4.978A	1.802A	599.553	92.106%	0 RPM	<6.0 dB(A)	54.95°C	0.998
12.108V	5.020V	3.312V	4.993V	650.935	44.78°C	115.14V
6	54.560A	5.988A	5.985A	2.005A	719.431	91.405%	700 RPM	19.0 dB(A)	41.22°C	0.998
12.090V	5.012V	3.308V	4.983V	787.084	55.93°C	115.11V
7	63.566A	6.992A	6.986A	2.207A	839.318	90.584%	710 RPM	19.2 dB(A)	42.71°C	0.998
12.117V	5.008V	3.305V	4.977V	926.561	59.37°C	115.12V
8	72.793A	7.998A	7.992A	2.410A	959.262	90.006%	830 RPM	21.8 dB(A)	43.66°C	0.999
12.101V	5.003V	3.303V	4.972V	1065.785	61.14°C	115.12V
9	82.456A	8.504A	8.514A	2.413A	1079.235	89.225%	1165 RPM	30.9 dB(A)	44.56°C	0.999
12.087V	4.998V	3.300V	4.969V	1209.563	62.35°C	115.13V
10	91.696A	9.023A	9.007A	3.541A	1199.085	88.348%	1310 RPM	34.5 dB(A)	45.36°C	0.999
12.071V	4.991V	3.297V	4.940V	1357.237	63.43°C	115.14V
11	101.758A	9.032A	9.017A	3.545A	1319.046	87.460%	1525 RPM	38.6 dB(A)	45.51°C	0.999
12.056V	4.988V	3.294V	4.936V	1508.169	64.11°C	115.12V
CL1	0.099A	18.028A	18.003A	0.004A	151.890	84.244%	730 RPM	19.5 dB(A)	43.86°C	0.990
12.158V	5.017V	3.345V	5.070V	180.298	59.99°C	115.14V
CL2	99.934A	1.003A	1.002A	1.002A	1219.611	88.433%	1345 RPM	34.7 dB(A)	45.66°C	0.999
12.071V	5.002V	3.288V	4.986V	1379.139	61.47°C	115.14V

Load regulation on every rail is tight, approaching the HX1200i's performance. That's to be expected, since both PSUs are based on the same platform.

The fan's noise is kept very low, even under high temperatures. It helps that the passive mode lasts a long time, and that the fan only speeds way up during our full-load and overload tests. In no case did we record a >40 dB(A) reading, which is amazing for a 1200W PSU.

Given its 80 PLUS Platinum badge, we expect this PSU to deliver at least 90% efficiency with 20% load, 92% with 50% load, and 89% at full load. As you can see from the table above, only the last condition isn't satisfied, mostly because of the high ambient temperature we test at. In comparison, the 80 PLUS organization tests at unrealistically low ambient temps of 23°C +/-5°C.

In any case, this is a solid-performing PSU that will easily deliver its full power for prolonged periods, even under high operating temperatures. At the same time, its fan won't be a major noise source.

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

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

16 Comments Comment from the forums

davidgirgis

In the Conclusion, 'TO' should be 'To'; and 'demands' should be 'depends'; and 'product' should be 'protect'.
Reply
grozzie

Not another plug/connector change!. I, like many people on this site, build custom PC's, part of which includes sleeved cables. One bug bear is 2 wires into 1, which is a in in the arse. I personally like the HXi series of Corsair PSU's which only have one such connection. I also think the 24 pin ATX supply is outdated and needs revision. I can't see the point of supplying motherboards with 3.3 and 5v rails. If only 12v was supplied with any or all voltage reduction made on board life would be so much simpler and neater. By providing more noise reduction at source (the PSU) gives Motherboard manufacturers an open cart to reduce the quality of voltage regulation i.e capacitor quality, on the motherboard. Is there really a need for another PSU on the market?
Reply
panathas

On the specifications table it says: "Efficiency: 80 PLUS Gold, ETA-B", which is wrong since this is a Platinum PSU.
Reply
Aris_Mp

yes we didn't pay much attention to the 80 PLUS efficiency certification :)
Reply
10tacle

^^What are you talking about? Register and get on Corsair's support forums:

https://sso.corsair.com/idp/AuthnEngine#/authn

Of course they have a customer support phone number: 888-222-4346 (North America customers).

Anyway, back on topic, first the $#@! miners have negatively impacted our GPU market, and now they may negatively impact our PSU market. :fou: What makes this really aggravating is that the PSU makers really can't prove a PSU was used 7x24 for heavy mining operation.

Worse, even if PSU vendors like Corsair offer a mining-specific PSU for less money with just say a 2-3 year warranty, nothing would stop the miners from buying the full 10-year variant. This mining craze is becoming a real pain to we PC enthusiasts.
Reply
10tacle

You are making everyone's head hurt. If you want to complain about Corsair, then do so on Corsair's customer support forums and social media. Also, just FYI, Tom's only reviews what is sent to them. They do not go "cherry pick" buy products and review them. For someone who is an alleged "original reader" of Tom's I'd have expected you to understand that.
Reply
jonnyguru

jellwood... aka: Alex Jones.
Reply
jonnyguru

20057343 said:
Not another plug/connector change!. I, like many people on this site, build custom PC's, part of which includes sleeved cables. One bug bear is 2 wires into 1, which is a in in the arse. I personally like the HXi series of Corsair PSU's which only have one such connection. I also think the 24 pin ATX supply is outdated and needs revision. I can't see the point of supplying motherboards with 3.3 and 5v rails. If only 12v was supplied with any or all voltage reduction made on board life would be so much simpler and neater. By providing more noise reduction at source (the PSU) gives Motherboard manufacturers an open cart to reduce the quality of voltage regulation i.e capacitor quality, on the motherboard. Is there really a need for another PSU on the market?

Bro.. You're all over the place. :D

So only the 24-pin is pin incompatible with the Type 3 cables. And yes... it's because of the extra sense wires. If you're really going to get all wound up about having to do 2-to-1 wires when doing custom cables, you know what you should do? Don't do 2-to-1 wires. They're only sense wires. The lack of them doesn't prevent the PSU from working. It'll just make your voltage regulation "as bad" as any other PSU that doesn't have the sense wires.

Yes. The ATX spec is out of date. But Intel wrote it and nobody is going ot implement a new standard without Intel's blessing. They even released a whole new ATX design guide last month that changes almost everything (T1 timing, T3 timing, standby efficiency..) but DID NOT TOUCH the pinout (they made -12V "optional", but that's hardly much of a change).

Reply
beatnutz

Jellwood: I find it hard to believe that someone who does not know how to write a proper sentence is preparing any students for anything. Let alone the ACT.
Reply
beatnutz

Jellwood: I find it hard to believe that someone who does not know how to write a proper sentence is preparing any students for anything. Let alone the ACT.
Reply

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