Lian Li Silent Force 850W PSU

Results

For a change we've also tested 20 percent load as well - this is what the 80Plus program also tests and it should be a good indication to a "typical" idle load, that a PC spends most its time in. Here the efficiency just noses over 80 percent, however the PFC is sub 90 at just 84.5 percent.

The rest of the tests - 50, 75 and 100 percent load scenarios are very good however, providing upwards of 85 percent efficiency except for 3.3V/5V weighting, which tests more if the PSU can do what it claims, rather than a real world situation. The PFC is still 90+ throughout, which is very good, but comparatively actually fractionally on the low side as we're used to seeing mid to high 90s on average.

At 20-75 percent loads the fan remained very, very quiet and exceptionally cool running - there's literally zero fan noise and we were hard pushed to hear anything except a quiet rush of air, but only when we dropped our ears right to it. As the load levels increased, naturally the temperature did too but the sides, base and air expelled from the back only became warm to touch rather than hot, which is quite surprisingly given the limited airflow and noise.

As importantly, the voltages are excellent - all of which are consistently level without dipping, even under high loads. The only disappointment is that on 100 percent load for the 12V rails, the 3.3V and 5V rails become extremely sensitive to physical movement. It was very strange as the whole unit would just cut out entirely if we touched the connectors or barely moved cables.

This made voltage readings a little difficult for just these two and left to its own devices it would carry on happily for as long as we left it under full load though. We're not entirely sure why this is, and it happens on both the 12V #1 and #2 or #3 and #4 loads, and while we never faced a problem up to this point and the realistic likelihood of constantly loading to 100 percent it low, Lian Li doesn't appear to have allowed much overhead in this 850W design.

Lian Li also only rates the PSU to 25˚C at 100k hour MTBF, even though its website says 40˚C. The manual states 25˚C not including the cooling fan and only to 80 percent load. While the MTBF factor is a completely arbitrary number either Lian Li is more open than most about the lifetime capacity of it's PSU or it simply doesn't compete here quite as well.