I've had it for almost 2 years, it hasn't made a sound, it's completely silent and hasn't given me the slightest problem, I recommend it with my eyes closed

Very good and quality power supply. I would like a few more ports while also its cables are quite short and do not reach easily for cable management

You can't expect a modular power supply at this price; judging it in its category, it is flawless.

A very reliable power supply. After almost 2 years of use with 10600k and 1050ti with light overclocking on both, it has shown stability.

Ίσως η καλύτερη επιλογή σε αυτά τα λεφτά .
https://www.youtube.com/watch?v=4-loVajgKKw&t=2s

Very satisfied with the job I want it for, it's just right, I don't play games on the PC, but I do all the other things. Silent.
I haven't stressed it yet, but I don't think there will be an issue.
For anything that comes up, I will get back to you.
The build is as follows: Gigabyte B550 Aorus Elite V2 (rev. 1.0) Motherboard ATX, Ryzen 5 5600G, 2x8GB Corsair Vengeance RGB Pro DDR4-3600MHz, Samsung 970 Evo Plus SSD 500GB M.2 NVMe PCI Express 3.0, Be Quiet System Power 9 400W Full Wired 80 Plus.
Recommended by me.

Initially, I can say that I was impressed at 56 euros when I first bought it and it really does what it promises, performance.
Yes, it is 80 Plus Bronze but that doesn't mean reliability, the only thing that bothers me is that it has Chinese capacitors.

Update 25/7/2025: This power supply has at least a 2-year warranty from the manufacturer Be Quiet, which is relatively little.

I was forced to change the power supply because I needed something more powerful with 80 Plus Platinum certification and 850 Wattage.

In the year 2025, I would not recommend anyone to buy it because for its age the System Power 9 is old and will not deliver what it promises compared to 2020 - 21 - 22.

I am very happy that my computer is working again, since a lightning strike had destroyed my last transformer. The installation was quite easy and I did it by myself. Good price too!

Bought to replace an identical 600W unit, because it didn't have enough GPU outputs to accommodate both cards (3060 and a 570) and I was forced to use an adapter, but I wasn't comfortable with 24/7 mining use. Both dogs haven't made a peep. Quietly (of course when I'm not mining - because even if they grunt, it's drowned out by the GPU fans) :D I will hardly choose another brand for a power supply.

I've been using it for 2 weeks and it's super. Silent (nothing like the previous "simple" one I had on my old PC). It has super wiring.

Excellent power supply completely silent at the threshold of dead silence and very stable in performance. Highly recommend without a second thought!

Very good for the money! Installed in a tower for simple use, mostly browsing the internet. Recommended!

At first, it worked very well for me, after 3 months of use now it crashes when I open games like GTA or CoD. As soon as I installed my new power supply, everything got fixed, I was using it on an R5 3400g, now it's most likely that mine was defective

I have purchased so far for different builds two 400W and one 500W. The small ones have been used in builds with B460 ASROCK and Intel core i3 10300, and 8gb at 2666 a simple system with one m.2 250gb drive and one 1Tb HDD at 7200rpm.

Up to the writing of this review, I am absolutely satisfied, as they have shown no instability.

The 500W has been used in a build with Ryzen 5 2600, with gigabyte b450 ds3h, 8gb Gskill ripjaws V at 3200, gigabyte GeForce gtx1060, m.2 250gb and 1Tb Seagate barracuda and the same applies to the 400W units. I have no instabilities, blue screens, and the like. It is definitely a vfm power supply.

I had a cx600, I installed a be quiet system power 9 700watt.
Really the best, stable voltages at 12v, silent as can be, the water cooling makes more noise, I'm thinking of generally putting be quiet fans. It doesn't raise crazy temperatures, it has 2 pci cables that each have a second pci connector, quite convenient to be honest because you have fewer cables hanging.
So far 100% satisfied.
The only thing that bothered me but I don't consider it a downside is the CPU cable, quite shorter than the previous one but it doesn't bother me either.

After this purchase, I became a fan of be quiet! with the main criterion being silence, as I spend many hours on the computer and need quiet. Now I will also change the case fans to be quiet!

Perfect! Very quiet, as I was initially checking if the fan was spinning. A positive aspect, despite being fully wired, is the black cables it has and that the cables are very flexible. Stable without fluctuations in voltage! I definitely recommend it!

I'll say one thing. If the screen is off, you easily forget the PC is on. NOTHING CAN BE HEARD. Quality construction, all the cables are black instead of the circus with the colorful ones, they have a fabric covering so they don't get tangled together. The only possibly negative thing is that personally I would have liked the CPU cable to be 1 cm longer.

Coming from another company's 500w 80 bronze 5-year, I got this because the fan in the old one started buzzing. At a load of 200w, it is completely silent, the measured consumption is 10w less than the other one, during gaming or aida+furmark. The CPU cable as well as the 24pin gave me a hard time getting them behind the case, I needed them to be 3cm longer. Other than that, it handled 3 drives at once.

It is the best vfm power supply for €68. I am speechless. It is silent. Get it, I highly recommend it.

I have written about the 600W model, and I am also writing about the 700W model that I recently purchased for a new system. It has a very respectable 12V output and is measured at 40. If you have a water-cooled system with silent system fans, you will forget that the PC is on. The power supply is COMPLETELY SILENT, and even in stress mode, it remains silent. This particular model has long, sleeved cables, and its connections are double what you will need. It was used in a 2700X-Vega 64-water cooling-9 RGB fans-32 RAM-2xHDD-1xM2 setup. Plus, there is an immediate difference in the electricity bill (of course, if you still have DEI, you won't notice it)... It reminds me of the good old days of Cooler Master/Thermaltake; now, with the same money, you can't even get an 80 Plus White from big companies, and if it's Plus, they just rebranded it in the warehouse.

Dog, the power supply for the price I got it for (67 euros). It delivers a combined power of 672W on the 2 12v rails, while on the 3.3v + 5v rails it provides 130W. I have it on an FX 8300 @ 4.4 and an R9 280x TOP edition from Asus that is overclocked from the factory, all the currents are stable, and the power supply doesn't make a sound. Excellent product all around.