Pros

Amazing "power-to-weight" ratio; ultra-quiet at idle despite no zero-fan mode; very efficient

Cons

Despite new larger fan, still loud under heavy loads; short warranty

Star Rating

Performance

box

We always make it a point to test products in a real-world setup like those our readers might be using. We don't use open test benches or stands, and we don't use the same huge ATX case to test every component, from low-profile coolers to dual video cards in SLI. As we like to say, it's important to choose the right tool for the right job, and testing a product in a scenario that doesn't replicate its real-world application may overstate strengths or hide weaknesses.

So, with that in mind, here's the system we used to test the SX500-G:

  1. CPU: Intel Core i7-4770K
  2. Motherboard: AsRock Z97E-ITX/AC
  3. Video Card: EVGA GeForce GTX 1080 8GB Founders Edition
  4. RAM: Crucial 2x4GB Ballistix Sport VLP DDR3-1600
  5. Solid State Drive: OCZ Trion 150 960GB
  6. Case: Silverstone Raven RVZ02B-W
  7. Optical Drive: Samsung Internal Slim DVD Burner
  8. CPU Cooler: Reeven Steropes
  9. Operating System: Windows 10

We originally built this system up for our High-End ITX Assembly Guide, which used the SX500-LG ver. 1 power supply. While we thought the RVZ02 case was quite an impressive showcase of the SFX-L form factor, the power supply itself was not all we had hoped it would be, as discussed on the previous page. While the SX500-LG V2 that we've been using in this test system was in improvement, it still wasn't perfect, as you'll see in the benchmarks.

Below we've provided photographs of both the SX500-LG V2 and the new SX500-G installed in our RXZ02 test bed: 

Installed

As you can see, while the SX500-LG fit fairly well, the SX500-G was truly a breeze to install in a system that can fit larger SFX-L units. It allows you to spend a bit less time doing cable management, for better or worse. After we took these photos, we realized that the challenge of installing the SX500-LG forced us to do a better job with those cables! Where the SX500-G will really offer huge ease-of-use improvements is in small cases designed around ATX power supplies. Our favorite is the SilverStone SG13, which you certainly can install an ATX power supply, but you probably won't want to! Team up the SX500-G with SilverStone's PP08 adapter bracket, and getting your power supply in will be a breeze! Essentially, it's a "universal" power supply, in that it can be used in any system. The one thing that the SX500-G loses in comparison to the SX500-LG is the fashionable logo plate, which it turns out simply could not be affixed without going outside of the SFX size spec, according to SilverStone.

We chose our components based on the fact that the GTX 1080 is the most powerful class of GPU we recommend for slim or ultra-compact systems, and awhile the Core i7-4770K is an older CPU at this point, its power profile isn't all that different from Intel's latest Core i7 processors, which we think these systems can handle with proper CPU cooling. Once we had a sense of how much this tandem drew at load, we chose a 3DMark test scenario that would get our system to hit right around the 50% "sweet spot" of these 500W PSUs, namely 250W. They should be at maximum 90% Gold efficiency at this point. The scenario we used was the 3DMark Fire Strike Extreme built-in stress test.All right, time to turn these systems on and see what the SX500-G can do!

Benchmark

At idle, this unit wasn't actually more efficient than the SX500-LG, which is not too surprising given that there's just not much room to improve things when you're only drawing around 30W. The big news is that it's far quieter, dropping from 40.5db to 35.5db, which is simply a tremendous improvement. Note that the system had other fans in it (both our Reeven Steropes CPU cooler and GTX 1080 Founders Edition run their fans constantly), so in order to isolate noise from the PSU, we placed our noise meter 3" from the fan grille, which in the RVZ02 chassis is conveniently exposed through the case panel. If you were to stand one meter away from these systems, you probably wouldn't be able to distinguish which component was making extra noise, but you'd certainly know that the PC with the SX500-LG was louder.

SilverStone graph

Under stress, the tables turned slightly. Here, the SX500-G was actually a bit more efficient than the SX500-LG, drawing 3W less, but it was also much louder. We placed our ears right up against the PSU fans to verify what the sound meter was picking up, and it was clear that this was no fluke. The smaller 92mm in the SX500-G was clearly running at much higher RPMs than the 120mm unit in the SX500-LG. At left we've included an image of the fan profile that SilverStone published on its website and included on the SX500-G's box. Based on our testing, we'd have to say this just isn't accurate. There's no way the fan was operating at under 1000RPM when our system was drawing around 250W.

Critical update: SilverStone confirmed to us after this review was published that the fan profile graph published on its website and shown on the SX500-G's packaging is indeed incorrect. SilverStone provided us with the full data table, and we have created a fan profile graph that accurately reflects the actual fan behavior in the SX500-G, as shown below.

SX500-G Fan Profile

It turns out that during our testing, our system likely pushed the PSU up to 1401RPM, which is tripped once the fan exceeds 250W, so our hunch was right - it was not running at under 1000RPM. While we commend SilverStone for providing us with its proprietary data, we're a bit disappointed that incorrect data made it onto the product packaging. Ultimately, the noise level is a bit of a disappointment, and this is one of the tradeoffs you must consider when packing this much power into a tiny enclosure. Remember, this wasn't even at the ragged edge of the PSU's power rating, but rather right at 50% load. To put this noise level in perspective, we measured our GPU fan and our CPU fan from a 3" distance, and found our GTX 1080, which was loaded at 100% in this test, generated 46dB, while the CPU fan was running at 42dB. So at 48dB, the PSU was the loudest component in the system, and we'd wager that SilverStone probably could tighten up the fan profile a bit to get the noise level down until power draw and internal temperatures were closer to maximum. Then again, we've never known SilverStone to be the kind of company that takes a lot of chances with reliability.

Conclusion

Overall, we came away incredibly impressed by the SilverStone SX500-G. In its attention to detail, SilverStone has crafted a new SFX unit for the ages, and we have no doubt that it will remain on the market for years to come, just like SilverStone's original Gold-rated SFX units released in 2012. With its more robust selection of ports and cables, a full 500W on the 12V rail, as well as its extremely quiet idle noise levels, it's a great PSU pick for any compact system. We just wish that SilverStone could tweak the fan profile a bit to lessen noise at load, but otherwise, it's really the ideal SFX power supply. Being that it has no serious SFX competition at the 500W output level, fair pricing becomes an open question, but its official MSRP of $100 is right in line with Corsair's $90 SF450 and the $120 SF600, which seems fair to us, if not particularly aggressive.

The SilverStone SX500-G SFX Power Supply, which has just been released, is available for $104.99 shipped from Amazon, as of our publication date. While we think it's more than powerful enough for any system you could run in an ITX enclosure,  SilverStone also markets a higher-wattage version, the SF650-G, which is selling for $134.99 shipped from Amazon. It offers the most power you'll find in any SFX power supply, in case you really want to crank your PC up to "11"!

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