Corsair SF600 Power Supply Review

Reviews
By Aris Mpitziopoulos
published

We recently evaluated Corsair's SF450, which left a good impression on us. Now it's time to test the family's flagship SF600, which can deliver 150W more power using exactly the same cable configuration.

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Transient Response Tests

Advanced Transient Response Tests

For details on our transient response testing, please click here.

In these tests, we monitor the response of the PSU in two different scenarios. First, a transient load (10A at +12V, 5A at 5V, 5A at 3.3V and 0.5A at 5VSB) is applied for 200ms while the PSU works at 20 percent load. In the second scenario, the PSU is hit by the same transient load while operating at 50 percent load. In both tests, we use our oscilloscope to measure the voltage drops caused by the transient load. The voltages should remain within the ATX specification's regulation limits.

These metrics are crucial because they simulate the transient loads a PSU is likely to handle (such as booting a RAID array or an instant 100 percent load of CPU/GPUs). We call them "Advanced Transient Response Tests," and they are designed to be very tough to master, especially for PSUs with less than 500W capacity.

Advanced Transient Response at 20 Percent

Swipe to scroll horizontally
VoltageBeforeAfterChangePass/Fail
12V11.974V11.853V1.01%Pass
5V5.034V4.974V1.19%Pass
3.3V3.330V3.266V1.92%Pass
5VSB5.034V4.985V0.97%Pass

Advanced Transient Response at 50 Percent

Swipe to scroll horizontally
VoltageBeforeAfterChangePass/Fail
12V11.963V11.836V1.06%Pass
5V5.014V4.959V1.10%Pass
3.3V3.310V3.239V2.15%Pass
5VSB5.014V4.962V1.04%Pass
Image 1 of 5

Deviations on the +12V rail are significantly improved compared to the SF450, while differences on the other rails are small. In general, the SF600 performs well. In particular, the 3.3V rail registers amazingly low deviations.

Here are the oscilloscope screenshots we took during Advanced Transient Response Testing:

Transient Response At 20 Percent Load

Image 1 of 4

Transient Response At 50 Percent Load

Image 1 of 4

Turn-On Transient Tests

In the next set of tests, we measure the PSU's response in simpler transient load scenarios—during its power-on phase.

For the first measurement, we turn off the PSU, dial in the maximum current the 5VSB can output and switch on the PSU. In the second test, we dial the maximum load the +12V can handle and start the PSU while it's in standby mode. In the last test, while the PSU is completely switched off (we cut off the power or switch off the PSU by flipping its on/off switch), we dial the maximum load the +12V rail can handle before switching on the PSU from the loader and restoring power. The ATX specification states that recorded spikes on all rails should not exceed 10 percent of their nominal values (+10 percent for 12V is 13.2V, and 5.5V for 5V).

Image 1 of 3

The 5VSB slope is almost perfect, and small steps in the +12V tests aren't enough to spoil the bright overall picture. 

Aris Mpitziopoulos
Contributing Editor

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

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38 Comments Comment from the forums
  • dudmont
    Are these small SFX designed for systems with ITX boards? I understand your complaints about the 8 pin cpu cables, but your complaints about PCIe cables doesn't make sense in light of the fact that no ITX board can handle more than one card. If you're using a micro-atx board, you can use a standard size PSU.
    Reply
  • powernod
    Wait a moment. Only 2 pci-e cables with 1 connector each one? That means that only one high-end GPU can be supported.
    Just like Aris said, what is the reason to go from the SF450 to the SF600, if you can't put another GPU?
    +150 watts only to feed SATA devices???!!
    Reply
  • LePhuronn
    A 600W PSU can drive a couple of high-end graphics cards and an overclocked CPU. But with only two PCIe connectors, the SF600 natively supports just one enthusiast-class GPU

    Yeah, because this PSU is intended to power top-end Mini ITX systems which can only run a single GPU. I thought that was obvious, or is there some standard requirement to review a component entirely in isolation without considering its application?
    Reply
  • LePhuronn
    Wait a moment. Only 2 pci-e cables with 1 connector each one? That means that only one high-end GPU can be supported.
    Just like Aris said, what is the reason to go from the SF450 to the SF600, if you can't put another GPU?
    +150 watts only to feed SATA devices???!!

    Headroom. I'm current running an original Titan and i5 2500 on Silverstone's ST45-G modualr PSU, and I'm only overclocking the Titan. However, I'm moving the Titan to a new build with a i7 6700K and I don't feel too comfortable pushing both the CPU and the GPU as far as they'd go with only 450W. I'd have no worries with a 600W.
    Reply
  • g-unit1111
    17905577 said:
    Are these small SFX designed for systems with ITX boards? I understand your complaints about the 8 pin cpu cables, but your complaints about PCIe cables doesn't make sense in light of the fact that no ITX board can handle more than one card. If you're using a micro-atx board, you can use a standard size PSU.

    Yes. They're designed to work in ultra compact cases like the Silverstone Raven RVZ01B, RVZ02B, as well as the Fractal Design Node 202. I think Corsair is even releasing their own ultra compact case at some point. But the trend is that cases are getting smaller, not bigger. Sure there will always be a market for ATX and EATX, but with Steam Box, you will start to see more of a demand for this type of case. With each generation from here on out, you'll see single cards be just as powerful as a dual card system. So you can get by with no SLI.
    Reply
  • turkey3_scratch
    Great Wall really is great. It's incredible that this compact unit blows most 600W units out of the water. It's not so much as "headroom" but if you take this PSU vs the SF450, and put that PSU on a machine with the same load, which will have the lower ripple and tighter voltage regulation? The SF600.
    Reply
  • jimmysmitty
    17905717 said:
    Wait a moment. Only 2 pci-e cables with 1 connector each one? That means that only one high-end GPU can be supported.
    Just like Aris said, what is the reason to go from the SF450 to the SF600, if you can't put another GPU?
    +150 watts only to feed SATA devices???!!

    A 980Ti is recommended, by nVidia, to have a 600W PSU and that is for the stock 1000MHz speed 980Ti. If we consider the fact that the majority of 980Tis come stock with 10-20% overclocks then a 600W SF PSU would be preferable for a high end ITX build. I can tell you a lot of people throw 980Tis into ITX builds.
    Reply
  • turkey3_scratch
    Also let's not forget peak efficiency at 50% of a power supply's capabilities, so the SF600 is ideal for that.
    Reply
  • RedJaron
    Peak efficiency may be around 50% load, but you're forgetting that this is an 80 Gold unit. While it's at least 90% efficient at 50% load ( the graphs looks to be a bit above that ), it's still ( at least ) 87% efficient at 90% load. You're only losing about 5% efficiency between the two here. That only means it draws a few more watts from the wall. Delivery inside the case remains unchanged.

    GPU mfrs' recommended PSU capacities are always inflated to compensate for the mediocre ( or worse ) PSUs that flood the mainstream and OEM space. A 980 Ti will pull at most 250W - 275W, depending on OC, during a heavy gaming load. Torture tests can go above 300W, but no one mines with an ITX box. Adding the 130W you'll see from the rest of a typical i7 system, you'd rarely see this go above 400W. That's an 88% load on a 450W PSU. Tight, but certainly not risky or dangerous. As I constantly remind people, my i7 + 290X test bed runs just fine on a 500W PSU, and that GPU is a lot hungrier than the 980 Ti.

    The only legitimate use for this PSU, with it's 600W but very limited cables, that I can think of is a heavily OC'd ITX gaming box built in a case that requires an SFX PSU. I can't find a single Z170 or X99 ITX board that has more than an 8-pin CPU power connector, so the PSU's limitation there shouldn't matter. Split the load 300W for the GPU, 250W for the CPU and rest of the system and you duck in just under the power limit. But again, that only makes sense if you MUST use a SFX PSU. Plenty of small cases support full size ATX units, where you have a lot more selection.

    This feels as though either Corsair is trying to fleece some customers into spending more than necessary or they got lazy in expanding a product line by increasing capacity without also taking the trouble to re-tool the cabling.
    Reply
  • Aris_Mp
    In my opinion a 600W PSU (even an SFX one) should have 4x PCIe connectors, because VGAs like the GTX970 and GTX980 consume 160W-200W at worst case scenario, so a couple of them can be easily supported.
    Reply