Corsair RM850x (2024) ATX 3.1 Cybenetics Gold PSU Review

TweakTown Rating: 94%

Our Verdict

If you like Corsair products and are looking for a new PSU for your new mid-tier build, the RM850x ATX 3.1 PSU should be on the top of your list.

Pros

• Cybenetics Gold and A ratings
• Zero RPM mode and integrated PSU fan controller
• ATX 3.1 standard
• Rubycon 105C Japanese capacitors
• Individually sleeved cables and 10-year warranty

Cons

• 12V-2x6 connector only has two sense wires, limited to 300 watts

Should you buy it?

AvoidConsiderShortlistBuy

Buy at Amazon for $129.99 USD

Buy at Amazon for $184.99 CAD

Buy at PC Case Gear for $209

Introduction, Specifications, and Pricing

Corsair has sent over one of their newest ATX 3.1 PSUs in the 850-watt flavor, this time sporting a new grille design matching the rest of their 2024 lineup. The RM850x sports both a Cybenetics Gold and an A rating, which should make this PSU a solid option for those who have mid-range CPUs and GPUs.

The RMx series also comes in 750W and 1000W if those are more your fancy. Pricing for the RM850x currently has an MSRP of $169.99; however, you might be able to pick one up for less. So why don't we take the RM850x out for a spin and see how she handles? Let's go.

Best Deals: Corsair RM850x Power Supply

	Today	7 days ago	30 days ago
	$129.99 USD	-	-	Buy
	$184.99 CAD	-	-	Buy
	$129.99 USD	-	-	Buy
	$129.99 USD	-	-	Buy
	$209	$209	$209	Buy
	Check Price	Check Price	Check Price	Buy
	Check Price	Check Price	Check Price	Buy
	Check Price	Check Price	Check Price	Buy
	Check Price	Check Price	Check Price	Buy
* Prices last scanned 3/15/2026 at 8:42 pm CDT - prices may be inaccurate. As an Amazon Associate, we earn from qualifying purchases. We earn affiliate commission from any Newegg or PCCG sales.

Packaging

19

Looking at the outside of the box that the RM850x is in, there is the typical Corsair yellow and black color scheme.

19

The backside of the packaging shows all the efficiency and fan noise levels of the RM850x. Also shown are 5 of the key features that Corsair has pointed out.

19

Opening up the packaging, we see another Corsair staple, the PSU in corrugated paper/cardboard for protection. One can assume the cables are under the cardboard on the right. Also, Corsair wants you to use the QR code, which you scan with your smartphone camera app, to view the manual.

19

Fully embossed braided cables on every run are present. Included cables are:

• NEMA 5-15P to C13 power cable
• Modular ATX Cable (24-pin) 610mm(± 10mm)
• EPS / ATX 12V 8-pin (4+4) 750mm(± 10mm) (2)
• PCIe 12V-2x6-pin (12+4) 650mm(± 10mm)
• PCIe 8-pin (6+2) 650mm(± 10mm) (3)
• SATA (4 Connectors) 850mm(± 10mm)
• PATA (3 Connectors) 750mm(± 25mm)

19

Removing the PSU from the box, is that corrugated paper/cardboard we saw earlier? The RM850x is also wrapped in clear plastic to make sure any debris won't find its way inside.

Outside the Corsair RM850x 2024 ATX 3.1 PSU

19

With all the packing materials removed from the RM850x, we can see the fully reworked fan grille design, with a gray 140mm fan behind. Corsair has also placed its name in small print in the center right.

19

Here we have one of the sides of the RM850x, which is pretty uneventful. The large stickers hide two screws on each side, which I will be removing for a closer look inside.

19

Next up is the cable input side of the RM850x. The 24-pin motherboard connection is broken out into 18 and 10-pin inputs. Next up is the 12V-2x6 connector, which does have all four sense pins, interesting. Next up are five 8-pin connections for either CPU or PCIe. Lastly, in the lower left, are three 6-pin SATA/PATA inputs.

19

The underside of the RM850x displays the product informational sticker, indicating that the RM850x features 70.8A on a single 12V rail.

19

The rear of the RM850x reveals a few key features. Firstly, Corsair emphasizes that the RM850x is designed to operate silently at low to moderate loads out of the box. Therefore, don't be alarmed if the fan doesn't spin up. Next, we have an interesting knob on the backside next to the power input; this knob is for manual fan control.

Inside the Corsair RM850x 2024 ATX 3.1 PSU

19

Now, cracking open the RM850x, we are greeted with a Corsair fan! OMG, a company put their fan inside their PSU. Sorry, I am just flabbergasted, that's all. The NR140HP is a fluid dynamic bearing 140mm 12V DC fan that Corsair regularly sells, which is nice to see.

19

The OEM for the RM850x is from Channel Well Technology, or CWT. The design layout is good with a good amount of heatsinks that provide ample cooling to the various parts of the RM850x.

19

Focusing on the two large capacitors, which are from Rubycon, are temperature rated for up to 105 °C and have also been rated at 400V at 470 microfarads each for a combined total of 940 microfarads.

19

The main transformer, which Corsair has placed its logo upon, is sandwiched between the VRM and power input sections.

19

Looking at the VRM section a bit more closely, we can see two VRM coils as well as the various supporting capacitors.

19

Lastly, the PFC, or the Power Correction Factor, is tucked away in the corner, which is much needed and required in today's modern PSUs. The PFC helps maintain and detect the current at a specific frequency to help ensure power efficiency.

Installation and Finished Product

19

Using the PSU test bench for this testing, the CPU, which is the Ryzen 9 7950X, was set to auto vcore to allow the CPU to boost as high as it thermally can. The 16-core, 32-threaded CPU maintained a 5.2 GHz boost clock during most of the test while running the AIDA64 Engineer System Stability Test. The AMD Ryzen 9 7950X's wattage ran up to a max of 176.4 watts according to HWINFO64, but averaged out to about 170.24 watts. The AM5 motherboard used here is a B650 AORUS Elite AX. The test RAM is a 32GB kit from Patriot, specifically the Viper Venom running at DDR5-5600M/T.

The test GPU, NVIDIA RTX 3090 FE, was power-limited at 43% via the NVIDIA App to control the system wattage. On average, the NVIDIA RTX 3090 FE drew about 150.3 watts with a maximum wattage of 152.7 watts. The power drawn from the wall was measured using a Killawatt P3 digital electrical usage monitor, which recorded a total system wattage of between 420 and 430 watts during the testing period, with an average usage of 425 watts. Calculating efficiency, we found that the total system wattage was 395 watts, divided by the 425 watts of the PSU load average, resulting in 92.9% efficiency at a 50% PSU load. This RX850x is a solid gold-rated PSU, nicely done, Corsair.

All testing was completed using Aida64 Engineer's System Stability Test version v7.35.7000 for over 21 hours, with an ambient temperature of 20 °C. Other monitoring software used was HWiNFO64 v8.16-5600, TechPowerUp GPU-Z v2.67.0, and CPU-Z 2.16.0.x64.

Final Thoughts

19

So, in closing, was the Corsair RM850x 2024 edition a good ATX 3.1 PSU? Well, yeah, it was. Considering its specifications, despite having only a 300W 12V-2x6 power cable, I don't see an issue at all, unless you are running an RTX 4090 or RTX 5090 (which you shouldn't be running on an 850W PSU). Also, Corsair has opted to make the PSU fan adjustable via the knob on the back of the RX850x, which is something that is not available with other PSUs in its class. This feature, coupled with the high-quality NR140HP fan, shouldn't give the end user any problems, if at all.

The RM850x is a high-quality PSU with pricing that is pretty much on point, thus making the Corsair RM850x an excellent pick for a mid-range gaming PC.