This is probably the quietest fan-driven PSU I have ever tested. At even full load and high ambient, the fan only produced low noise levels that can in no way be described as annoying to my ears. The L8-500W also achieved a generally decent performance with high enough efficiency and tight voltage regulation with good ripple suppression; that is, if its mainstream status is taken into account. Be Quiet!'s decent asking price and the PSU's performance allowed it to achieve a pretty high price/performance ratio in the corresponding graph, placing it ahead of many mainstream units, and others. I also didn't take noise performance--the L8-500W easily takes one of the top spots there--into consideration in the aforementioned graph. Be Quiet! again proved that their products really do feature a truly silent operation, which is why noise-haters prefer them over the competition. I also liked the selection of caps in the secondary side. While many manufacturers use really cheap Chinese caps to lower the cost of their budget unit by as much as possible, BE Quiet! used nothing but Teapo ones; these may be Chinese but have proven their reliability and are, as such, considered the best non-Japanese solution.

This product does, like every other product, have its grey areas. The most crucial one is that although Be Quiet! claims it is Haswell ready, and the PSU works fine according to their testing in real Haswell systems, the results I acquired by following Intel's official testing procedure for Haswell compliance say otherwise as the unit failed to keep all of its rails in spec. Here I should note that it performed really well in the above test for a group-regulated PSU, but it ultimately failed because the 5V rail fell too low and ripple on the same rail exceeded the limit. It is, in my humble opinion, almost impossible for a group-regulated PSU to pass the Haswell compliance test because Intel set the bar too high for most budget PSUs.

To sum up, the L8-500W is for you if you want a reliable PSU that performs well, comes with great support, and very little noise. It really is as simple as that. The techs over there at Be Quiet! know how to make inaudible products and this PSU is clear proof of that.