Power Supply Quality

As part of our testing, we also check output parameters are within specifications, as well as voltage ripple and line noise.

Main Output
Load (Watts) 151.04 W 376.73 W 562.06 W 747.72 W
Load (Percent) 20.14% 50.23% 74.94% 99.7%
  Amperes Volts Amperes Volts Amperes Volts Amperes Volts
3.3 V 1.81 3.39 4.53 3.35 6.8 3.3 9.07 3.29
5 V 1.81 5.1 4.53 5.04 6.8 5 9.07 4.94
12 V 11.25 12.06 28.11 12.05 42.17 11.99 56.23 11.97

Even though they complied with the design power quality guidelines, earlier SFX PSU designs displayed poor power quality figures. However, more recent models, like the SilverStone SX700-LPT and Corsair’s SF450, were greatly improved. Lian Li’s even more powerful SP750 now delivers excellent power quality figures, easily comparable with those of very good ATX units.

Line Regulation
(20% to 100% load)
Voltage Ripple (mV)
20% Load 50% Load 75% Load 100% Load CL1
12V
CL2
3.3V + 5V
3.3V 3% 8 10 12 14 12 18
5V 3.15% 10 14 16 18 12 18
12V 0.75% 8 12 18 38 36 12

We recorded a maximum voltage ripple of 38 mV on the 12V line under maximum load but much lower figures at lower loads, suggesting that the components were getting thermally stressed. Ripple figures on the 3.3V and 5V lines are lower, barely reaching 18 mV. The voltage regulation of the 12V line is impressive, at just 0.75%, but Lian Li somewhat neglected the 3.3V and 5V lines, the regulation of which is slightly above 3%.

Conclusion

Lian Li took a very strange approach for their first SFX entrance into the power supply market with the development of a premium PSU with a very high-power output. The SP750 is an SFX design meant to power systems that could even be featuring an RTX 3090 – assuming that one can find and afford such a card in the market today. The use for small form factor 750W units powering big cards is small, as few users actually build very powerful yet compact machines, however there are only a few companies that develop and market similar high-output SFX PSUs, meaning that the SP750 does not have as much competition as an ATX PSU would. The use of Helly Technology as the OEM is also a question mark, as we do not often see them used for consumer power supplies.

The quality of the Lian Li SP750 is excellent. Both externally and internally, Lian Li’s designers were very careful with their selection of components and with the manufacturing process. As a result, the SP750 is not just reliable but also very aesthetically pleasing. It is actually strange that Lian Li only covers the SP750 with a 5-year warranty, whereas most other manufacturers offer up to 10 years for products of just as good quality.

When it comes to performance, the Lian Li SP750 does not disappoint. It offers excellent electrical performance, with power quality figures that we expect to see only with top-tier PSU designs. The energy conversion efficiency is exceptional, with the unit easily justifying its 80Plus Gold certification. What is even more impressive is its resilience to high internal temperatures, which hardly affect the unit’s conversion efficiency. The only troubling performance aspect of the SP750 is the cooling fan, which will easily become audible when the PSU is heavily loaded, even with the unit inside a relatively cool system.

Lian Li is targeting a niche market with the release of the SP750 and we believe that the company expects most of their sales to be in conjunction with their own SFX-compliant cases – after all, the SP750 aesthetically is a perfect match for them. Even though the high-performance SFX PSU market is very small, there are also very few competitors right now, meaning that Lian Li only has to worry about a handful of other products and not hundreds of them. The retail price of the SP750 is $140, a very reasonable tag for an SFX PSU with that high a power output.

Hot Test Results (~45°C Ambient)
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  • kdogg4536 - Tuesday, July 13, 2021 - link

    $140 I think I will pass until they build up a proven track record for that much money. One good review is a nice start but not enough to get my $140 Reply
  • kaidenshi - Tuesday, July 13, 2021 - link

    I'd take it at that price. I paid $99 for the 550W Focus SFX PSU in my mini-ITX build, and I would have gladly paid $50 more for a 750W from a company with a better reliability record if it had been available at the time. Reply
  • Foeketijn - Tuesday, July 13, 2021 - link

    It always interests me, how these business plans enfold. If I was Lian Li and wanted to make such a A grade >100 dollar PSU, I would go to the best name brands, who are coincidental also in Taiwan.
    Make sure it has for example the best cooling fan and only Japanese parts. Just to make sure that first new product sets the stage for whatever comes next.
    Especially For a Taiwanese company, how come it's a Chinese PSU with Chinese parts (other than the fan). Why take the risk? Why not support your local industries?
    I try to avoid buying stuff from China as much as possible because I don't like the politics, and slavery. We vote with our spending. And I'm not Taiwanese. Fascinating
    Reply
  • Jasonovich - Tuesday, July 13, 2021 - link

    I don't think geopolitical sentiments have any value on an IT website. Most brand names have their operations outsourced to China and some very fine quality electronic components come from China.
    If you're into main stream media and you believe everything your government says that's fine, enjoy your poison but slavery?
    What about Nike, Addidas, Apple, the list is long.I assume you're OK with Israel and apartheid ?
    Reply
  • Questor - Tuesday, July 13, 2021 - link

    If it stays on topic, geopolitical statements can be valuable information to inform the consumer. When it veers off topic, then it has no value. Reply
  • Foeketijn - Tuesday, July 13, 2021 - link

    Interesting reply. I am not saying China can't make propper stuff. I am just saying, the best PSU's are made in Taiwan. Why gamble with an relatively unknown producer.
    And ofcourse geopolitics play a role. I don't think Australians will outsource much to China ATM. Just like Indians won't likely outsource anything to Pakistan.
    It's not black an white. And has it's place on any website including IT. As long as it's ontopic.
    Off topic, you guessed right, I never buy anything from those brands. And that list is indeed very long. I am not against China, I don't like most things about globalisation (I do like that I can write this to you), and I hate slavery. Can't proof you didn't use slavery? I won't buy.
    Reply
  • WonkoTheSaneUK - Thursday, July 15, 2021 - link

    "What is strange here is the presence of three PCI Express connectors, because the SP750 clearly has the power output for two middle-range graphics cards but the lack of a fourth connector deprives users from that choice."

    3 PCIe connectors isn't strange at all.
    750W is enough power to run a Nvidia RTX3080 or RTX3090 graphics card, and some of the AIB cards require 3 such connectors, instead of Nvidia's new, smaller single 12-pin connector, used on the "Founder's Edition" cards.
    Reply
  • eldakka - Sunday, July 18, 2021 - link

    I think the comment was about ONLY having 3 connectors on a 750W PSU, as it is capable of running 2 GPUs each requiring 2 connectors for a total of 4, which this PSU doesn't have.

    I don't see it as a problem for gamers, as they'd most likely go for a single high-power card (max 3 connectors needed), but gaming isn't the only use case out there ;)
    Reply
  • faaaaq - Wednesday, July 28, 2021 - link

    I just grabbed the 011 Mini deal from Newegg that came with this, for like $200. My first SFX PSU and man is it teeny tiny. Powering my heavily-overclocked 5950x, moderately overclocked 3080 FE, nine RGB fans, two water pumps (GPU and CPU are each on their own AIO cooling loops), and 4000mhz DDR4. No issues so far but Ive only had it since yesterday, replacing my Seasonic 750w ATX PSU and CoolerMaster H500. I had not looked up reviews before purchasing the case + PSU combo, so its nice to see the PSU ended up being very high quality. Nice. Reply

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