Pros, Cons And Final Verdict
Corsair knows how to get the best out of every OEM it collaborates with. In this case, the outcome is an amazing SF family that sets new performance standards in the underrepresented SFX form factor. We've known about the SF PSUs for a while now, since one of them is used in Corsair's Bulldog system, and we believe the company did the right thing introducing this line-up. After all, many enthusiasts are interested in smaller form factors these days.
Up until now, the performance of SFX PSUs couldn't match the ATX-based competition due to size restrictions. But this changes with Corsair's SF PSUs. Both of the current models easily stand up to popular ATX power supplies with similar capacity.
The SF600 registers amazing performance with super-tight load regulation at +12V, very good ripple suppression on all rails and low deviations on transient loads, which every PSU is faced with on a daily basis. In addition, it doesn't have a problem doing its job under extremely tough conditions. In fact, Corsair states that this unit can deliver its full power continuously at up to 50 °C ambient. Given our test results, we concur.
No PSU is perfect though, and the SF600 has some issues we'd like to see addressed. For starters, it uses the same cable configuration as its smaller sibling, the SF450. We find this odd because too-few connectors mean you can't fully exploit the power supply's 150W-higher output. You'd rightly expect the higher-end implementation to include more cables. With only a couple of PCIe connectors, you're still limited to a single high-end graphics card when the SF600 should have no trouble supporting a couple of them. Moreover, it would be nice if this PSU was equipped with an additional ATX12V connector to support motherboards that need extra connectors besides the EPS one. On top of that, four SATA connectors are too few for a 600W unit. We are well aware that the modular panel's dimensions are a limiting factor. But clever design work could get around some of these issues.
Another downside is the overly aggressive fan profile, which renders the PSU noisy under taxing loads. Taking into account the SF450's quiet operation, we didn't expect the SF600 to behave so differently. We noticed that even under the same load levels, the SF600 is noisier than the SF450. Clearly, Corsair has adjustments to make to its fan control circuit.
Despite our critiques, the SF600 is a good SFX PSU that serves up very high performance, even if it doesn't offer a clear advantage over the SF450 because it uses the same cable configuration. Worse, the SF600 generates a lot more noise under the same operating conditions. Our recommendation is to stick with the SF450 for now. Even if you spend more on the 600W version, you'll probably have a hard time fully utilizing its increased capacity.
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Aris Mpitziopoulos is a Contributing Editor for Tom's Hardware, covering Power Supplies.
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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???!!
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?
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.
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.
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.
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.