Cold Test Results

For the testing of PSUs, we are using high precision electronic loads with a maximum power draw of 2700 Watts, a Rigol DS5042M  40 MHz oscilloscope, an Extech 380803 power analyzer, two high precision UNI-T UT-325 digital thermometers, an Extech HD600 SPL meter, a self-designed hotbox and various other bits and parts. For a thorough explanation of our testing methodology and more details on our equipment, please refer to our How We Test PSUs - 2014 Pipeline post.

The SilverStone SX800-LTI is surprisingly efficient, even for an 80Plus Titanium certified unit. We recorded an average efficiency across the nominal load range (20% to 100% of the unit's capacity) of 93%, with the unit maintaining a conversion efficiency above 94% when the load is between 300 and 500 Watts. The low load efficiency is relatively good but there is room for improvement, as the efficiency drops below 80% with loads lower than 40 Watts.

SilverStone designed the SX800-LTI to be semi-fanless, i.e. the fan only spins when the load or temperatures are high enough to necessitate it. 80Plus Titanium units usually work in fanless mode with a load up to several hundreds of Watts. The cooling profile of the SX800-LTI is way more aggressive than most, starting the fan when the load is higher than just 200 Watts, even when the temperatures are low. Still, that is high enough to generally ensure that the fan will never spin-up when the system is idling or performing simple tasks.

The sound pressure readings are a little higher than what we would like from a unit that is most likely going to be installed in HTPC systems, but they are not unnatural for a compact PSU with such a massive power output. Even when it fan starts spinning, the SX800-LTI maintains comfortable user levels with loads up to 550-600 Watts in room temperature. The PSU does get loud when heavily loaded, but it is highly unlikely that this PSU will ever find itself running at such loads for prolonged periods of time. 

The SilverStone SX800-LTI SFX-L 800W PSU Hot Test Results
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  • WithoutWeakness - Thursday, January 18, 2018 - link

    Now that we have multiple options for medium-to-high output SFX power supplies I would like to see more case manufacturers design cases that drop ATX support and only support SFX PSUs. It's been amazing to see the designs that smaller case makers and newcomers have made when designing for the smallest cases possible and SFX PSUs have enabled them to dedicate less space for bulky ATX PSUs. Reply
  • DanNeely - Thursday, January 18, 2018 - link

    On larger cases saving an inch on the PSU is a much smaller return than it is on mITX systems. Between the higher prices and much lower availability of SFX/SFXL PSUs I don't think we'll ever see widespread adoption of them in mATX/ATX cases. Reply
  • jtd871 - Thursday, January 18, 2018 - link

    WithoutWeakness wasn't talking about larger cases. He was talking about cases without support for ATX PSUs. Reply
  • cjb110 - Friday, January 19, 2018 - link

    Not sure they can do that and still call it an ATX case, which then makes marketing a potential nightmare, that might be one reason. Reply
  • Valantar - Monday, January 22, 2018 - link

    There are a couple from Lian Li, and the Kimera Industries Cerberus is nice (if you can get it), but yeah, the selection is limited. I'd love to see more SFX+mATX or SFX+ATX cases. Why not? Reply
  • jrs77 - Thursday, January 18, 2018 - link

    I've got the 500W SFX-L PSU from Silverstone and it's the sweetspot for a single GPU-system imho. Reply
  • meacupla - Thursday, January 18, 2018 - link

    At this wattage, it's more like "We crammed in 800W, because we could".

    Even if you assembled the most powerful mITX system, using an Asrock X299E-ITX, an i9-79xx and 1080Ti and overclocked those, you would still be inside of 600W power envelope at full load.
    (Going off of Coolermaster's power calculator)
    Reply
  • edzieba - Thursday, January 18, 2018 - link

    Don't forget SFF cases for mATX and ATX. While 800W is not enough for the quad Titan-V beast (smallformfactor DOT net/forum/threads/kimera-industries-cerberus-the-18l-matx-usa-made-enclosure.454/page-180#post-78461), you you drop back to a mere two Titan Vs - either on an mATX board or with ITX and PCIe Bifurcation - you can cram serious compute into an even smaller case. Reply
  • jordanclock - Thursday, January 18, 2018 - link

    Because conversion efficiency is best at about 50% load, so you use a PSU like this to stay within the most efficient load range. Reply
  • Holliday75 - Thursday, January 18, 2018 - link

    How much does that translate in savings on my electric bill? How quickly would that offset the cost of a higher wattage PSU running more efficiently? Reply

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