Performance Analysis

All high-end PSUs perform well these days, so we needn't dwell too much on the results, as differences are typically much of a muchness. The German firm's new unit has good voltage regulation, with a maximum fluctuation on its 12V rails of just over one percent – nothing to worry about at all.

The two 850W units we've compared this one to are 80 Plus Platinum rated (a fair comparison going by price), and so it's no surprise to see the Be Quiet! unit bottom in nearly all of these tests. However, it's only about 1.5 percent behind on average, and it doesn't tail off at low loads, which means it's suitable for long idle periods.

The Straight Power 11 850W's ripple suppression capabilities are best described as average, at least as far as high-end units go. It is well within the ATX spec limit, of course, but the graphs clearly show that even better is possible.

An area where the Be Quiet! stands out is in noise. There are not many meaningful differences in the graphs between this unit and the others (which are more efficient, remember). From a more subjective standpoint, the fan, while always on, remained inaudible up until around 600W load (about 70 percent).

Conclusion

Unfortunately, the Straight Power 11 is a decent power supply whose appeal is severely diminished by the high street price of £165. As a comparison, the EVGA SuperNova 850 P2, a supply better in almost every area, is only £142. In the face of this, even the £150 pre-order price at Scan can't really save it; this Be Quiet! PSU needs to be £130 before it gets a look-in for an award or recommendation. Don't believe us? The Corsair RM850x has 80 Plus Gold certification, fully modular cabling, and twice the warranty duration of this one but costs £120. Be Quiet! may highlight its build quality and fan, but these things aren't enough to close such a large gap in price.