The Corsair HX850 80Plus Platinum PSU Review

Conclusion

Corsair is aiming the entirety of the HX series, including the HX850 that we reviewed today, towards overclockers and advanced enthusiasts. These groups of users primarily value reliability and stability, but also need high overall performance, and are usually not dissuaded by a hefty price tag. The HX units are designed around that concept - the platform is primarily focused around the longevity of the PSU above everything else but without forgoing other performance aspects.

The overall electrical performance of the Corsair HX850 is exceptional. Even with the PSU heavily loaded under adverse operating conditions, the power quality readings that we took were excellent, with minimal voltage ripple appearing on all of the voltage lines and very strong regulation. Our readings were impressive but not unexpected of a high-quality modern PSU. The HX850 is not going to break any performance records here but pinnacle electrical performance is not the purpose of this series - Corsair has the AX series for that.

Our sample did not fully meet the 80Plus Platinum certification with an input voltage of 230V/50Hz, failing to surpass 94% efficiency at 50% load. As most companies do, Corsair is having their units tested and certified for an input voltage of 115V/60Hz and this specific unit has been officially tested and awarded an 80Plus Platinum certification, so there is nothing suspicious going on here. Apparently, the company’s engineers optimized the platform for an input voltage of 115V, as the lower requirements make it easier to achieve a better efficiency certification. Regardless of that, the conversion efficiency of the HX850 can definitely be characterized as excellent, with our sample sustaining an average efficiency of 92.7% across its nominal load range.

Although we feel that its heatsinks and overall thermal design could use an improvement, the high efficiency allows the Corsair HX850 to display very good thermal performance - perhaps even a little too good. The thermal control is very sensitive when the internal temperatures of the unit are high, pushing the 135 mm fan to its limit in order to keep the internal temperatures as low as possible. With the maximization of the unit’s reliability and stability being the primary design focus, that is not surprising, as even a few temperature degrees can mean years of difference on the lifetime of some electronic components, especially that of capacitors. The downside here is that the HX850 can become quite loud when forced to operate inside a very hot ambient environment.

At room temperature, the thermal behavior of the HX850 is entirely different, with the unit’s thermal control not even turning the fan on up until the load reaches almost half of the unit’s rated capacity.

The retail price of the Corsair HX850 currently is $160 (MSRP $200), which is a fair price for a high quality 80Plus Platinum certified unit that comes with a 10-year warranty. 80Plus Platinum units can nowadays found for less but most manufacturers have their leading designs priced around this price point and the HX850 is more than capable of giving the competition a run for their money.

The Corsair HX850 should be into the shortlist of anyone seeking a powerful, efficient, and very reliable PSU that will be the heart of their gaming/workstation system for many years.

Recent Power Supply Reviews

AnandTech tests a good number of power supplies each year, mostly in the popular power ranges (650-850W) with a few reviews now-and-again for small form factor parts or larger behemoths. Here are the power supplies we have reviewed in the last twelve to eighteen months.

• [link] The Corsair HX850 80Plus Platinum PSU Review (this review)
• [link] The Enermax Revolution SFX 650W PSU Review
• [link] The Seasonic PRIME Titanium PSU (650W, 750W, 850W) Review
• [link] The Riotoro Onyx Power Supply Review: 650W & 750W Tested
• [link] The BitFenix Whisper M 450W & 850W PSU Review
• [link] The Silverstone ST30SF & ST45SF SFX Power Supply Review
• [link] The Zalman ZM1200-EBT 1200W Power Supply Review
• [link] The SilverStone SX700-LPT SFX 700W PSU Review