Hot Test Results

For our power supply testing, 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 post.

The energy conversion efficiency of the Lian Li SP750 is remarkably stable, dropping an average of just 0.4% with the unit operating inside our hotbox. The degradation is greater at higher loads, naturally, but there are no signs of significant thermal stress.

The cooling fan of the Lian Li SP750 starts almost immediately after powering on the PSU into our hotbox, as expected from its thermal control circuitry. Noise levels are tolerable at first but the speed of the fan increases quickly, reaching maximum speed with a load of about 400 Watts. As the fan cannot spin any faster, the internal temperature of the units starts climbing even faster, reaching very uncomfortable temperature figures when the PSU is fully loaded in such an environment. The protective circuits did not shut down the unit and there was no indication of excessive stress to any of its performance indicators, yet we would not recommend allowing the PSU to ever run anywhere near that hot.

Cold Test Results (~25°C Ambient) Quality & Conclusion


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  • meacupla - Tuesday, July 13, 2021 - link

    okay, in that case, I want to see someone's matx, sfx, dgpu compute pc then. Reply
  • Spunjji - Tuesday, July 13, 2021 - link

    It does sound like a niche within a niche (within a niche) Reply
  • Questor - Tuesday, July 13, 2021 - link

    I don't have a picture of one. I can tell you they exist. Go to Small Form Factor dot net and there you will find SFF cases designed for bifurcation of the single PCIexpress slot. There are riser cables designed for it as well. It certainly has nothing to do with playing games. It is a real thing though I agree a special situation scenario. Reply
  • thestryker - Monday, July 12, 2021 - link

    While I'm fairly confident that the PSU would last a long time the warranty period is disconcerting. Now this might just be due to the contract Lian Li signed with the ODM, but even the midrange PSU I got 5 years ago for my system came with a 10 year warranty. If this foray is successful for Lian Li it will be interesting to see if they go back and lengthen the warranty.

    As always I really appreciate the quality of the PSU reviews done here, and the high ambient testing brings in a unique dynamic.
  • jonnyGURU - Monday, July 12, 2021 - link

    Lian Li's first PSU? Lian Li has had PSUs since 2008!!! They literally have two SFX-L PSUs on the market that were launched just five years ago! LOL! Reply
  • kaidenshi - Tuesday, July 13, 2021 - link

    You may wish to re-read the article instead of skimming. This is their first non-L SFX PSU. Their SFX-L models were addressed in the article:

    "A few years ago, it entered the market with SFX-L power supplies, but the demand wasn't quite there."
  • Oxford Guy - Tuesday, July 13, 2021 - link

    The fan is a mistake.

    Ball bearing fans have no place outside of radiators in consumer systems and even then it's questionable.

    I have also read the claims that they are more prone to damage if they are knocked hard or dropped — and that they become noisier over time (unlike FDB and other high-quality alternatives). I am not sure if either are true but the noise performance of this unit, fresh and undamaged, is enough to show that the fan is a mistake.
  • Spunjji - Tuesday, July 13, 2021 - link

    I believe they've gone for the least expensive option that would still survive the high temperature environment inside a small PSU. Sleeve bearing fans die too quickly in such circumstances, and anything resembling FDB probably involves the sort of cost increase they'd want to avoid.

    Personally I'd be happy enough replacing the fan myself if the noise became an issue, but it's a shame for the sort of end users who rely on warranties.
  • Oxford Guy - Tuesday, July 13, 2021 - link

    ‘anything resembling FDB probably involves the sort of cost increase they'd want to avoid.’

    The company clearly did want to avoid it. The consumer can avoid the product in return.
  • Samus - Tuesday, July 13, 2021 - link

    As an EE, this thing is practically pornography for me. Beautiful unit. Reply

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