Practical testing …
The installation went smoothly, only the ATX cable is as usual a bit shorter, so it can be quite a bit tight in larger cases. However, this is absolutely no problem for the Lian Li O11 Dynamic Mini, since the power supply is installed directly behind the motherboard, so you only need a short 24-pin ATX cable.
All cables fit and the plugs are very tight, so you have to pull a little harder to loosen them.
To check the quality of the power supply, we check the voltages in idle and under load with the program HWiNFO, among other things. To be able to stress the CPU and the graphics card separately, we chose Prime 95 as the CPU stress test and the Heaven benchmark for the graphics card. HWiNFO and Prime 95 can also be downloaded from our Overclocking Software section.
Testsystem …
The test system consists of the following components …
| AMD Mainboard | ASRock X370 Killer SLI |
| CPU | Ryzen 7 1800X |
| RAM | 2x 8GB DDR4-2666MHz CL16 |
| Graphics card | Sapphire R390X Nitro+ |
| Case | Lian Li O11 Dynamic Mini |
| Power Supply | Lian Li SP750 |
The voltages …
Before we look at the voltages in detail, let’s take a look at the voltage tolerances according to the ATX specification. These are +/-5% of nominal for both the +5V and +12V lines, resulting in the following limits. The power supply color codes and pinouts are listed in our forum at PC Power Supply Pinout.
| Voltage | Tolerance | Minimum | Maximum |
| +3.3V | ±5% | +3.14V | +3.47V |
| -5V | ±10% | -4.5V | -5.5V |
| +5V | ±5% | +4.75V | +5.25V |
| -12V | ±10% | -10.8V | -13.2V |
| +12V | ±5% | 11.4V | 12.6V |
Voltages at idle …
The system permits itself a little over 40W at idle. The voltages we determined are very slightly above the nominal value.
Voltages with Prime95 …
To ensure that the AMD Ryzen 7 1800X is also fully utilized, we use Prime95 in the SmallFFT test here. Here, the CPU draws a nice 120W. However, this does not affect the LianLi SP750 at all, the voltage remains virtually locked.
Voltages at full load …
Finally, we test our system under full load. We run Prime95 in the SmalFFT test and the Heaven benchmark simultaneously. The system now needs just under 250W and even with that, the power supply is of course completely unimpressed. At no time during the test did the voltage drop below 12V or 5V.
You can find out how much electricity costs for an economical silent PC or a real gaming monster with our interactive PC power cost calculator:
And the SFX PSU does look very good in our recently reviewed Lian Li O11D Mini case.
Let us now come to our conclusion.
Lian Li SP750 Result and general impression …