*As per our title, this will be an “overview” since we don’t have access to a load tester anymore, which as you know, is a must for any complete PSU review.* With that out of the way, let’s continue.

Today we are going to have a quick look at the Pure Power 11 FM PSU from be quiet!. The ‘FM’ designation refers to a ‘Fully Modular’ design with the main distinction that these units are made by CWT, while the other non-modular and semi-modular Pure Power units use FSP platforms. Also this new CWT platform is only available to be quiet!. From some quick research this is great platform without breaking the bank.

There are three variants to choose from and today we are looking at the 550W model (650W and 750W being the other two) that promises 80 PLUS Gold with an efficiency rating of up to 93.5%.


Be Quiet! is a premium brand manufacturer of power supplies and cooling solutions for your desktop PC. With numerous awards under their belt and are considered the best German power supply manufacturer from Germany since 2006 – proved by being awarded with no less than nine times in a row with “Manufacturer of the Year” in the power supply category by the readers of the well-known German hardware magazine PC Games Hardware. In the category “fans”, be quiet! earned the first rank for five consecutive times and belongs to the Top 3 CPU cooler brands for more than three years in a row. The community of Hardwareluxx also voted be quiet! as “Manufacturer of the Year” in the PSU category for four consecutive years.


Prices and Availability


At the moment of writing availability is a bit low but we are looking at around $90 for our test sample the 550W model from Newegg (or £79 from Amazon.co.uk).


Presentation and Specification


* Courtesy of their website


Pure Power 11 FM 550W offers peerless dependability and best-in-class features such as modular cable management. Whether you are assembling a very quiet system, upgrading your PC, or building a gaming system with a powerful high-end GPU: Pure Power 11 FM 550W offers the best combination of features at a very popular price.

* 80 PLUS® Gold efficiency (up to 93.5%)
* Modular cables for maximum build flexibility
* Two strong 12V-rails
* Silence-optimized 120mm be quiet! fan
* Advanced stability and voltage regulation thanks to LLC, SR and DC-to-DC
* Two PCIe connectors for powerful GPUs
* Full suite of top safety features
* Five-year manufacturer’s warranty


Visual Inspection & Installation


The overall packaging theme is preserved in line with most of their products, with a black background and a visual depiction of the actual item. The branding is excellent and on point.

On the back we have the detailed power delivery, the company intro, the Gold efficiency sticker and a q-code.

Inside the box, the PSU has its own protective bubble wrap bag while all of the cables are housed within the carboard divider.

As for the full accessory breakdown, we have:

1x User’s manual
1x Power cord
4x Philips screws
7x PSU cables

Now let’s zoom into the modular cables.

The 24 pin (20+4) main cable is the only one fully sleeved and the quality is excellent. It’s 55 cm long.

The CPU 8 pin (4+4) is the longest cable at 60 cm.

Now the PCI-E cables are 50 cm long and are in a 6+2 pin configuration.

Finally we have three SATA cables all 50 cm long with 15 cm connector spacing. This is the one that has the legacy FDD connector with two Molex and two regular SATA connectors.

The other two cables only use SATA ports and one has 3 while the other has 4 ports. That’s the beauty with a modular PSU, you can choose exactly what you need.

Check out this excellent OCD small detail: even the individual writing on each wire matches perfectly.

Now for the PSU. The 550W Pure Power 11 FM unit is fully compliant with the ATX12V v2.52 & EPS 2.92 specifications, so it is very efficient under incredibly light and light loads. It’s 160 cm long and it’s cooled by a 120mm rifle bearing fan (BQ QF2-12025-MS). From this angle we see the fan having a white rim ring which is an effective visual detail to disguinsh it from the older non-modular series for example.

This side has the company name nicely engraved while the whole enclose has a lovely powder metal texture to it.

The exhaust side has a honeycomb pattern and we have two subtle stickers above and below the power cord port.

On this side we have the whole surface covered with the specs and power delivery sticker.

Finally the panel side, has 8 sockets which are nicely labelled.

The connections are strong and secure.

Installation is straightforward depending on your enclosure. Our testing case has this modular design which means you can installed it from the outside which further simplifies things.

Here is the finished look. The all black cables are highly welcomed since they will colour match with most enclosures, if you care about this aspect as well.

The 8 pin CPU plug being flat can even be routed behind this SSD tray.

On the other side, the same cable reaches almost perfectly.

The same goes for the 24 pin but the PCI-E cables are on the limit and they are a bit to short for this case and only reached in this position.


Testing methodology


Without a proper load testing PSU machine, we cannot call this a full review. However that doesn’t stop us from trying to stress test as best we can, trying to squeeze as much wattage from the PSU to see if it will bulge.
Then we will measure the total wattage from the wall via our wattage monitor and then record the load noise coming from the PSU fan.

The most power hungry card we have with a rated TDP of +250W is an KFA2 GeForce GTX 480 Anarchy 1538MB DDR5 flagship, with a must needed custom Accelero EXTREME Plus 3-fan cooling setup from Artic Cooling. This is already overclocked from factory to an extra +60 MHz on the cores and +200 MHz on the memory.

The Ryzen 7 1700 CPU was overclocked to 3.70 GHz with a stable voltage of 1.325v.

A standard 3D benchmark will be used as well, in UNIGINE Superposition. Then to fully stress the system we will run a stability test for 2 minutes in AIDA64, with everything checked (FPU cache, GPU, CPU and RAM stress testing).

Hardware used:

CPU: AMD Ryzen 7 1700 AM4 – 8c/16t @ 65W TDP
CPU Cooler: Noctua NH-U12S chromax.black
RAM 16GB DDR4 T-Force Night Hawk RGB 3000 MHz CL16
Motherboard: ASUS ROG STRIX X370-F Gaming ATX @ BIOS 5220
Video card(s): KF2 GTX 480 Anarchy Accelero Xtreme Plus
PSU: bequiet! 550W Pure Power 11 FM Gold
Case: bequiet! Silent Base 802 Black
Case fans: 3x bequiet! Pure Wings 2 140 mm


OS: Windows 10 Pro x64 20H2
GPU Drivers: NVIDIA GeForce WHQL 391.35
Core Temp v1.16 – To see the temperatures in real time
CPU-Z v1.95 – To verify the CPU’s statistics
AIDA64 Extreme v6.23 – A popular total system stability test suite
Cinebench R15 – Popular CPU benchmark
Cinebench R20 – The new revised version optimised for the newer multi-core CPUs
MSI Afterburner v4.62 – To record the FPS and load/temperatures
UNIGINE SuperpositonThe latest 3D system benchmark


Testing, Results and Analysis


Let’s see how much power can we make the system consume in order to utilize the PSU’s potential. As you can see, even with an OC’ed CPU and already hungry GPU, we never saw above 390W (+/- 10-15W). This means you have plenty of headroom for even further overclocking on the CPU/GPU and/or multiple drive configuration. Also this will confirm their official statement that it is RTX 3090 ready as well.

As for noise output, even at max total system load stress testing with OC, we get really good numbers. The Pure Power 11 FM PSU does an excellent job here and it’s really quiet at ~ 60% Wattage load.




Given the nature of this overview, from our findings this PSU performed really well in the noise department, aesthetics and ease of use. The fully modular cables should reach most mid-sized builds and that’s the only complaint here because our testing case is quite large and the PCI-E cables were on the limit. The 120mm fan remained dead silent up to our 60-65% load test. The build quality is solid from the outside and the internals are great for this price range. Overall this unit will bring some nice competition in this segment and is definitely worth a look for most first time builders.

The good:

+ Excellent low noise output
+ Fully modular
+ Modern certification & efficiency
+ Great build quality & design
+ Appreciable value for money
+ 5 Years warranty

The bad:

– The PCI-E cables should be maybe a bit longer

Glob3trotters “Recommend” Award – 4.5 out of 5


Many thanks to Be Quiet! for supplying us with this test sample !


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