The Be Quiet! Straight Power 11 750W PSU Review: Excellent Quality, But Not Quiet

Conclusion

Be Quiet's Straight Power 11 is a unit designed to provide premium quality and performance to advanced users. It stands but a step lower than the company's top-tier series, the Dark Power Pro, which bears a higher efficiency certification. On paper, the Straight Power 11 is an impressive product, with impressive quality and performance specifications. It is also worthwhile to note that this is one of the very few premier PSUs that features multiple 12V rails. Whether the presence of multiple rails is a good thing or not is a topic for debate – multiple rails are safer, as the protection circuitry will not allow a single cable or connector to draw the entirety of the unit’s power output and be damaged. But on the other hand, balancing the load between the rails is necessary and certain devices that require very high currents may even be unusable with such a PSU.

Aesthetically, the Straight Power 11 is very subtle but does stand out a little, mostly due to its proprietary fan finger guard. Other than that, the designers did the best they could to make the PSU aesthetically pleasing without drawing unnecessary attention, keeping stickers out of sight and painting literally everything black. At least some of the cables, which are the most difficult part to conceal when building a PC, could be replaced by ribbon-like cables that are thinner and more flexible than sleeved cables, yet the designer opted for uniformity and added sleeving to every single cable of the PSU.

In terms of electrical performance, the Straight Power 11 PSU does perform very well overall. Its power output quality is very good, with our instruments showing well-regulated, stable voltage lines and good voltage ripple/noise filtering. The unit does honor its 80Plus Gold efficiency certification, easily meeting the energy conversion efficiency requirements regardless of the load. Our only complaint is that the very low load efficiency of the Straight Power 11 750W PSU is poor. This does not affect the unit’s efficiency certification because the significant efficiency drop happens below the nominal load range but, as systems are becoming more and more energy efficient in general as laptop-like power management techniques make their way to desktops, it is likely to significantly affect the overall energy consumption of newer and future computers.

Meanwhile when it comes to noise, it's worth noting that Be Quiet! is a company that primarily designs and markets products for low noise output. Which in the case of the Straight Power 11 series makes it difficult for us to give it a positive evaluation. The 750W unit that we reviewed is indeed relatively quiet under normal operating conditions, but that can change very quickly when the unit is heavily loaded or if the ambient temperature is high. Although the very aggressive thermal profile of the Straight Power 11 maintains very low operating temperatures that will surely improve the longevity of the PSU, it also places the Straight Power 11 behind the competition when it comes to acoustics, which does not bode well for a product that low noise operation is the basis of its entire marketing plan. In particular, the fact that the fan speed is load-driven rather than temperature-driven would seem to be to the PSU's detriment.

The Straight Power 11 PSU series stands at a peculiar place in the market, with Be Quiet! marketing it as a premium series, yet next to their actual premium series, the Dark Power Pro. The overall performance of the Straight Power 11 750W PSU that we reviewed today is by all means a good PSU, yet incapable of competing with the equally priced offerings of other manufacturers. Given that it's an 80Plus Gold-certified PSU, and considering its overall performance, the Straight Power 11 750W PSU should be retailing for less than $100 in order to remain competitive.