The new revision of the RM series is proportional and aesthetically identical to the unit it replaces, with the sole exception of adhesives. Corsair used the same chassis with beveled edges for almost all of its advanced power supplies. Corsair RM850x fully modular PSU – Satin black paint covers the frame, and the designer also chose neutral colors on the stickers, forming an elegant design. Other aesthetic improvements include raised parallel edges aligned with fan finger protection cables and a small unit pattern badge on the back of the frame. The chassis has been shortened from the previous version and is now 160 mm long, slightly longer than the length of a standard ATX power supply. This is unlikely to be a problem with a modern advanced ATX case, but users should be wary of atypical and inexpensive case projects.

In addition to the typical ac cable plug and the small on/off switch, we can only see a small badge with the unit model printed on it. Moving to the front of the frame we find it full of the many connectors for modular cables. The large 24-pin ATX cable is divided between two connectors. For the rest of the cables, there are basically two groups of connectors: one for 8-pin 12V PCIe/CPU connectors and one for 6-pin SATA/Molex connectors. The 12V PCIe and CPU cables can be inserted into one of the 8-pin connectors. However, the design is a little strange, with one of the 8-pin PCIe/CPU 12V connectors positioned between the 6-pin connectors, because the designer apparently thought that this was the most efficient way to arrange the connectors on the vertical board.

Most Corsair mid-range power supplies are produced by Channel Well Technologies (CWT), and RM850x is no exception. Previous versions of the RM850x/RM850 were also manufactured by CWT. This platform is largely based on the previous model, but there are several improvements, many of which are made to improve the efficiency of the unit. However, some modifications improve the long-term reliability of the unit and resistance to damage from external failures (AC).
RM850x heat sinks are suitable for high efficiency power supply with this type of output. Given its hybrid fan mode, it is obvious that the designer wanted the RM850x to have a reasonably wide range before the fan was needed. The input filter stage starts at the back of the AC outlet and continues on the main circuit board, with four Y capacitors, two X capacitors and two filter inductors. There are no surprises here, which is pretty much the standard for consumer-grade high-performance power supplies. CWT added a relay here to prevent the NTC thermistor after starting the power supply, giving the RM850x a slight increase in efficiency.
Corsair engineers designed the RMx series to provide an excellent balance between quiet operation, high-quality electrical performance and a reasonable price. In practice, the series bridges the gap between value and world-class performance products manufactured by Corsair. In this sense, it serves as an upgrade on the relatively simple but very reliable txm series, which offers quieter operation without the high price tag of an AXi series unit. Photo: Corsair

Although the main strength of the Corsair RM850x PSU lies in its quiet operation, we can not help but note that the electrical performance of the particular platform is outstanding. The RM850x far exceeded our initial expectations and provided exceptional power quality in our tests, with figures we typically see on products that sell for twice as much. In addition, we do not complain about the electrical efficiency of the platform, as it easily passed the 80Plus Gold certification requirements regardless of the input AC voltage.
the RM850x rewards its owner with excellent acoustic performance, generates no noise when lightly charged and maintains comfortable noise levels even when the load is high. However, if the load is excessive and the ambient temperature is high, the efficiency of the RM850x will degrade slightly, as the active components will begin to strain. But the only real scenario that meets these requirements is cryptocurrency mining, for which RM850x is clearly not the best option. Corsair RM850x current price: $130

The completely new Corsair RMx PSUs have ASM compatibility and carry out as effectively as their for-runners, while even increasing on them in some crucial areas, such as effectiveness at really light and light loads. The ML fan is a excellent improvement. Not that the riffle-bearing fan on the earlier generation was not fine, on the contrary, but ML fans are far better since they do not have any kind of issues working under high operating temperatures for prolonged intervals. One more main change is the 3rd EPS connector with the 850 W and 1000 W RMx models. We can’t help but wonder which CPU will require this many EPS connectors, but Corsair will have their arguments.

Competitors in the 850 W Gold category is tough. Nevertheless, the Corsair RM850x operates very well, placing third in our relative overall performance graph, with only a little gap to the Seasonic Focus Plus Gold of similar capacity and the EVGA SuperNOVA 850 G3, which the inferior G5 model has substituted. Basically, the RM850x and Focus GX-850 are the frontrunners in the 850 W group. An additional significant mention in this wattage selection is the Thermaltake ToughPower GF1 850, which also uses a CWT base.

Corsair’s RMx series is among the most well known in current day’s market place. The new versions will carry on this tradition if actual selling prices are retained the same since their efficiency is even higher and they are completely compatible with the newest ATX specification (v2.52). The only factor that needs tuning is the fan-speed profile below high loads on the minimal rails. There is simply no need for such a high maximum mixed power limit on the minor rails (150 W), and if Corsair were to lower the limit to 100 or 120 W, the Cybenetics noise score would increase as well. That having been said, ARGB does put a force on the 5 V rail, so lately, there is a requirement for beefier DC-DC converters for that rail.

Power supply get more expensive as their efficiency increases. If you play video games for a few hours each day, you should consider if you really need a Platinum or Titanium power supply because the price premium may be much higher than the additional energy costs. From a different perspective, it seems logical that the less electricity you use, the better. However, such option would cost more.

Since the voltages remained to be drop dead in sync at half load, or roughly 350–400 watts, we have very little—if anything—to complain about in terms of stability. However, we’ll rely on other reviews to provide you with some ripple testing, so you can be confident that the product will pass with best grades. Generally, kick-ass is a viable option for four rails, and the 850W model that was tested has enough power to support two very powerful graphics cards. Realistically, a 650 or 750 model would probably be a better choice as a recommendation for a PC with a single graphics card. If you like to overclock, get the 750W or this 850W model and allow some space for reserve.

Comparing the RMx pricing to more “standard” power supply, it may be a little bit slightly more expensive overall. But here’s why your money was a great investment: it was put toward a gold-rated PSU that flawlessly balanced your efficiency goals. The outstanding 10-year warranty simply further shows how much Corsair believes in this product.

The Corsair RM850x is absolutely unbeatable, at least in terms of what we can test. It checks off all the right boxes in terms of having a dark design, being modular, effective, and remarkably quiet. The RM850x definitely is pure gold, as stated on the box, thanks to that and the incredibly extended guarantee.

Weight -1.659 Adjustable Single/Multi 12V Rail -No ATX Connector- 1ATX12V Version- v2.4 Continuous output rated temperature- C 50°C Continuous power- W 850 Watts Fan bearing technology- Rifle Bearing Fan size mm-  140mm MTBF hours- 100,000 hours Multi-GPU ready- Yes Warranty -10 Years 80 PLUS Efficiency- Gold PSU Form Factor ATXi CUE Compatibility- No Zero RPM Mode- Yes Cable Type Low-Profile- All Black EPS12V Connector- 2 Floppy Connector- 1 Modular Fully PCIe Connector- 6 SATA Connector- 10 Special Technology- OVP (Over Voltage)
UVP (Under Voltage)
SCP (Short Circuit)
OTP (Over Temp)
OPP (Over Power) Protections  Yes