SilverStone SX650-G PSU Review: Lots Of Power In A Small Form Factor

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By Aris Mpitziopoulos
published

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Final Analysis

Years ago, SFX-based power supplies were limited to 350W or 400W, tops. Nowadays, we see 650W small form factor platforms that are not only reliable, but also relatively quiet. This is impressive because high-capacity PSUs need larger components inside for generating all of their output. It's natural, then, for SFX power supplies to have really crowded circuit boards. The problem with dense layouts is that they limit airflow quite a bit. Moreover, it's hard to find enough room for large heat sinks. As a result, building small, powerful PSUs with conservative fan profiles is immensely difficult. The best way to achieve this is minimizing waste heat with higher efficiency.

Because they're so small, it's unfair to compare SFX-based PSUs to standard ATX models. After all, large PSUs aren't constrained by as many physical variables, enabling better performance and quieter operation. Moreover, PSUs with small footprints tend to cost more. That's exactly the case with SilverStone's SX650-G, which sells for about $135 on Newegg. The SX650-G does perform well for an SFX power supply, and if it wasn't for the superb Corsair SF600 and SF600 Platinum, SilverStone's model would play alone in this segment.

However the SF600 sells for less money than the SX650-G and its overall performance is much higher. The SF600 might be louder in our cross-load tests, but it's a special case. Normally, load on the minor rails doesn't have a significant effect on fan speeds. In the case of Corsair's PSU, though, high loads on the 5V and 3.3V rails make the fan spin up. Fortunately, under normal usage, load on the minor rails is low.

The SX650-G can handle elevated operating temperatures, it is especially powerful for an SFX-based PSU, it boasts a fully modular design, it's quiet under light and moderate loads, and it fares well in our performance benchmarks. We would like to see SilverStone expose a second EPS connector and implement a smoother fan profile, since the existing one transitions between low and high speeds roughly.

Compared to the slightly cheaper Corsair SF600, SilverStone's SX650-G officially offers a 50W-higher capacity and two additional PCIe connectors. If you're building a PC with multiple graphics cards, that's a big deal. On the other hand, Corsair's SF600 serves up a much longer warranty period. Moreover, its overall performance is notably better. SilverStone needs a lower price tag to give the SX650-G a clear advantage. Otherwise, it's one of the few SFX models featuring 650W of capacity and four PCIe connectors.

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Disclaimer: Aris Mpitziopoulos is Tom's Hardware's PSU reviewer. He is also the Chief Testing Engineer of Cybenetics, and developed the Cybenetics certification methodologies apart from his role on Tom's Hardware. Neither Tom's Hardware nor its parent company, Purch Media, are financially involved with Cybenetics. Aris does not perform the actual certifications for Cybenetics.

Aris Mpitziopoulos
Contributing Editor

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

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8 Comments Comment from the forums
  • termathor
    Hey,

    I'm surprised a PSU with 85 degrees caps *and* only 3 years warranty is given such a good score ...
    Reply
  • jimmysmitty
    21233248 said:
    Hey,

    I'm surprised a PSU with 85 degrees caps *and* only 3 years warranty is given such a good score ...

    What I found interesting is the praise he gives the SF600 here yet the review he did of it gives it the same score as this unit, 7/10.

    He also had a ton of cons on the SF600 review that are just, well sorry but some are stupid. No Berg Adapter? Who even needs one of those these days? I doubt this PSU even has a berg adapter.

    So why does the SF600 which has better components (105c caps) and a better warranty (5 years) AND performs better apart from a heavier load on the not as used 5v and 3.3v rails causing the fan to spin up rate the same as this PSU?

    As mentioned in the article as well its cheaper and the Platinum version is, if you can find it, MSRP $10 bucks more (I found the Silverstone for $20 bucks less than the SF 600 Platinum on Newegg) and it has even better performance, components and a 10 year warranty.

    So again, how does this rate a 7/10 like a better PSU?
    Reply
  • crmaris
    When you criticise that someone talks stupid, you should be extra careful not to fall into the same trap :)

    Berg adapter, there are still some people that want it so why not include it? From the moment it is an adapter (so it doesn't alter the modular cables) and only costs some cents.

    The final rating isn't up to the performance only! But the overall picture including the product's usability. The SF600 is a great unit but has a major flaw. It only has two PCIe connectors! So you cannot fully utilize its 600W max power. While on the contrary the SilverStone unit has four of them. To give you an example it has exactly the same cable configuration with the SF450.

    Please take a better look at the epilogue of each of the reviews and you will get the meaning. The ratings are just a number to provide a rough idea and nothing more. Else I wouldn't bother write so much in the end of each review and list or pros and cons.
    Reply
  • jimmysmitty
    21233851 said:
    When you criticise that someone talks stupid, you should be extra careful not to fall into the same trap :)

    Berg adapter, there are still some people that want it so why not include it? From the moment it is an adapter (so it doesn't alter the modular cables) and only costs some cents.

    The final rating isn't up to the performance only! But the overall picture including the product's usability. The SF600 is a great unit but has a major flaw. It only has two PCIe connectors! So you cannot fully utilize its 600W max power. While on the contrary the SilverStone unit has four of them. To give you an example it has exactly the same cable configuration with the SF450.

    Please take a better look at the epilogue of each of the reviews and you will get the meaning. The ratings are just a number to provide a rough idea and nothing more. Else I wouldn't bother write so much in the end of each review and list or pros and cons.

    Was not stating that the person was stupid. Just that the con was stupid as the berg connection is not used in the majority of PC products much like how Molex is dying off in favor of the SATA connector. I have not seen a berg connection in a modern PC build for some time.

    As for the PCIe connectors, that's a fair "con". Notice I didn't mention it. I don't even think you can buy one like it for Corsairs PSUs and the only one I can think might have had a split single cable was the older CX series although I would personally never use one.

    So if we look at cons, then why did the SF600 get "dinged" for not having a ATX adapter but this did not?

    BTW I was incorrect. The SF600 has a 7 year warranty not 5. That's more than double, better grade components and cheaper. When I look at a PSU the biggest concern is build quality. Sure it would be nice to have some of the extras but I personally think build quality is the most important part. This PSU has a lower grade build, less warranty but hey it includes an out dated adapter and you can hook up two higher end GPUs to it so it rates the same.

    I personally don't feel like the two PSUs are in the same class nor deserve the same rating. To each their own.

    Let me clarify my reasoning. I don't want to sound like a jerk. Users will utilize this as a solid rating and a reason to buy or not buy. They wont always read the entire verdict or review.

    It is much like Amazon or Newegg reviews. People will look at the average star rating. They wont actually look at the actual reviews and if a product has 1000+ reviews I don't blame them however sometimes you can go into a product and look at the review and see that it may have no bearing on the products actual quality.

    Basically having a PSU that has lower performance, lower warranty and lower quality components rated the same as another with better quality will lead people who are not in depth tech savvy people to think they could buy either one and get the same quality.

    If you do feel that the rating/score is that unimportant than maybe the end should consist of pros/cons and a verdict with no score? However I do suggest to keep the pros and cons consistent as nicking one PSU for one thing but the other not feels a bit off.
    Reply
  • Dark Lord of Tech
    I have the SF600 it's a gem , the best in it's class in my opinion.
    Reply
  • Dark Lord of Tech
    Nice review , thanks ARIS!
    Reply
  • SilverStone Guy
    21233924 said:
    I personally think build quality is the most important part. This PSU has a lower grade build, less warranty but hey it includes an out dated adapter and you can hook up two higher end GPUs to it so it rates the same.

    I personally don't feel like the two PSUs are in the same class nor deserve the same rating. To each their own.

    In regards to build quality, the SX650-G is no less than that of SF600, besides the bulk cap being lower in temperature rating at 85C (which itself is a high quality brand and part btw, and we do extensive testing to make sure cooling is sufficient for it to last), everything else on the PCB is on par or better. And besides the core components, we've shown over at jonnyGURU, the fan we used in SX650-G is definitely better than SF600. The cables we included are also arguably better quality as well because they are more flexible.

    Many people don't realize increasing power output by 50W in SFX at the current 600W+ level is much more difficult of an engineering exercise than for ATX PSUs. I think in some ways this review article is also at fault for marginalizing SX650-G's 50W power increase over the SF600. Our SX600-G was released in 2014 and SX650-G in 2017, so that means it took three years to make an SFX PSU more powerful by 50W (while making it perform better, quieter, with more connectors, etc...) for around the same price!
    Reply
  • jimmysmitty
    21239216 said:
    21233924 said:
    I personally think build quality is the most important part. This PSU has a lower grade build, less warranty but hey it includes an out dated adapter and you can hook up two higher end GPUs to it so it rates the same.

    I personally don't feel like the two PSUs are in the same class nor deserve the same rating. To each their own.

    In regards to build quality, the SX650-G is no less than that of SF600, besides the bulk cap being lower in temperature rating at 85C (which itself is a high quality brand and part btw, and we do extensive testing to make sure cooling is sufficient for it to last), everything else on the PCB is on par or better. And besides the core components, we've shown over at jonnyGURU, the fan we used in SX650-G is definitely better than SF600. The cables we included are also arguably better quality as well because they are more flexible.

    Many people don't realize increasing power output by 50W in SFX at the current 600W+ level is much more difficult of an engineering exercise than for ATX PSUs. I think in some ways this review article is also at fault for marginalizing SX650-G's 50W power increase over the SF600. Our SX600-G was released in 2014 and SX650-G in 2017, so that means it took three years to make an SFX PSU more powerful by 50W (while making it perform better, quieter, with more connectors, etc...) for around the same price!

    Ok if you state the parts are equal to or better than a review by the same guy should result in an equivalent or better score correct?

    http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story6&reid=533

    http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story6&reid=477

    Even if you go through the SF600 got better performance numbers throughout, even hitting almost platinum efficiency.

    Yes FDB is better. The Corsair is able to run fanless in low loads so its a trade off.

    The cables are very objective. These days a lot of people swap the cables out with colored individually sleeved ones.

    This review had this that concerns me:

    Sky-high OPP and OCP on the 3.3V and 5V rails
    Over-temperature protection doesn't appear functional

    Not bashing it. Just based on the reviews I found outside of this one show it isn't the same grade as the SF600 Gold unit. If you feel it is truly equal or better then the numbers need to prove it where it counts, the performance. Cables and fans are one side. They don't always outweigh the cons though. I also think that if you feel that way that the warranty should match.
    Reply