Coolers and cooling fans aside, be quiet! are also renowned for their power supplies with exceptional reliability, especially the Dark Power and Straight Power lineup. Earlier this year, be quiet! has introduced its new Pure Power 11 FM lineup that comes with a fully modular design to make cable management easier. For the test this time, we’ll be taking a quick look at two models from the series, the Pure Power 11FM 650W and 750W just to see how well can it handle some of the latest hardware we have in our arsenal.


ModelPure Power 11 FM 650WPure Power 11 FM 750W
Continuous Power (W)650750
Peak Power (W)720820
Form FactorVersion 2.52Version 2.52
Form Factor EPS 12VVersion 2.92Version 2.92
Modular Cable ManagementYesYes
TopologyLLC + SR + DC/DCLLC + SR + DC/DC
Wire-free Design (DC-side)YesYes
Voltage (Vac)100-240100-240
Frequency (Hz)50-6050-60
Input Current (A)10/510/5
Power Factor at 100% Load>0.98>0.98
Compliant to Intel C6/C7YesYes
Standby Power Consumption (W)<0.14<0.14
Average Life Time (h/25°C)100,000100,000
Operating Temperature up to (°C)4040



The packaging for the Pure Power 11 FM is really simple overall, both the Pure Power 11FM 650W and 750W look pretty much identical in terms of the package design, except for the rated power and minor difference in the +12V rails. bAs be quiet! didn’t include too much information on the box, you’ll have to visit the official product page if you need more technical information on the product.

The Pure Power 11 FM 650W

Starting off with the Pure Power 11 FM 650W, the accessories that come together inside the box include the pack of modular cables, a 3pin UK plug AC Power Cord With 13A Fuse, a pack of screws, and a user’s manual. The modular cable pack includes all of the essential cables i.e 1 x 24-pin ATX cable, 2 x SATA power cables, 1 X SATA + 4-Pin Molex power cable, 2 x PCIe 6+2 Pin cable, 1 x 4+4 Pin EPS cable, and an unlabelled cable which is supposed to be the 4-pin EPS cable.

Nothing fancy about the cables but if I were to compare it to the Straight Power 10 600W we have from years ago, the all-black and flat modular cables are much more favorable when it comes to cable management because they’re mostly flexible and easier to bend to fit different angles.

For the Pure Power 11 FM 650W, although be quiet! never specifically specify the fan model used but it is according to them, a silence-optimized fan that will get the job done nevertheless. There’s nothing fancy about the design but it has pretty much everything you need for a decently built fully modular power supply.

The Pure Power 11 FM 750W

Moving on to the Pure Power 11 FM 750W, the accessories are pretty much the same as what you’ll get with the Pure Power 11 FM 650W – the 3pin UK power cord with 13A fuse, the modular cable pack, screws, and user’s manual.

The only difference we notice is the extra 4+4-pin EPS power cable while taking a closer look at all the included cables, which makes it suitable for motherboards that require 2 x 4+4-Pin EPS power cables to operate.

Design-wise, the looks and build quality of the Pure Power 11 FM 750W is technically identical to the 650W model. If we don’t look at the power rating and the specs on the label sticker, it’s almost impossible to tell the difference between both 750W and 650W models from just the look.

User Experience

CPUIntel Core i9-10900K @5GHz
MotherboardASUS ROG Maximus XII Apex
MemoryTeamgroup T-Force Dark Z FPS DDR4-4000
Graphics CardNVIDIA GeForce RTX 3070 / NVIDIA GeForce RTX 3070 Ti
Power Supplybe quiet! Pure Power 11 FM 650W / be quiet! Pure Power 11 FM 750W
Primary StorageKingston KC2000 1TB NVMe SSD
Secondary StorageWD Black 6TB
CPU CoolerCooler Master MasterLiquid ML360R
ChassisOpen Benchtable
Operating SystemWindows 10 64bit

For our synthetic benchmark tests, we will be doing the same set of tests using FurMark GPU stress test tool, ROG RealBench, Cinebench R23, Prime95 for 1 hour each for both the Pure Power 11 FM and the RTX 3070, RTX 3070 Ti respectively. The total system power draw for each of the tests is recorded and listed in the following table:

FurkMark 1.27ROG Realbench 2.56Cyberpunk 2077
GeForce RTX 3070384W416W395W
GeForce RTX 3070 Ti442W468W457W

From the test, we can see the total system power draw seems to be within what both the Pure Power 11 FM 650W and 750W can handle.

On the RTX 3070 setup, both power supplies can handle all the benchmarks with ease and no signs of performance hiccups can be observed. Similar behavior can be seen on the RTX 3070 Ti setup, which the Pure Power 11 FM 650W handled quite well despite the fact that the RTX 3070 Ti requires a minimum 750W power supply if we refer to the official specifications from NVIDIA. However, we don’t recommend pushing your luck on this as some RTX 3070 Ti might have a higher power draw, depending on how the AIB partners configure it.

The average temperature during load for both the Pure Power 11 FM 650W and 750W is always around the average 48ºC±, so overheating is the last thing to worry about if you’re using it normally – that excludes abnormal use like cryptocurrency mining or unauthorized tampering the unit. Load temperature aside, the barely audible fan noise is favorable for those who want to minimize the noise from their system and this makes it a considerable choice for low noise builds.


Performance-wise, both the be quiet! Pure Power 11 FM 650W and 750W did meet our expectations and are capable of handling the newer hardware that we have without any noticeable performance hiccups. Although 750W is the highest power rating the Pure Power 11 FM lineup has to offer, I believe it’ll suffice for most users or gamers nowadays? With the ongoing GPU shortage and insanely high price, you’re lucky enough if you can find a reasonably affordable RTX 3060, let alone an RTX 3070.

The build quality is decent and the fully modular design is something that I’d always appreciate, especially flat cables because of the convenience when it comes to cable management. Though I do have a small concern with the unlabelled cable that comes with the Pure Power 11 FM 650W, which can cause some inconvenience to users with less experience with the type of connectors on their power supplies.

As for the price, the be quiet! Pure Power 11 FM 650W and 750W retail at $99.99 and 114.99. Looking at how the Pure Power 11 FM 650W and 750W perform in our tests, I’d say that’s still a pretty fair price for the specs and what it is capable of, despite not having an insanely long warranty period like some of the competitors are offering.


Related Posts

Subscribe via Email

Enter your email address to subscribe to Tech-Critter and receive notifications of new posts by email.