Efficiency, Differential Temperature and Noise
Efficiency
Efficiency is defined by the power output divided by the power input and is usually expressed as a percentage. If a PSU were a 100% efficient (which none are) 500 watts of AC power going in would result in 500 watts of DC power coming out (with no waste heat to dissipate). In the real world there are always inefficiencies and power is lost in the form of heat during the conversion process. Newer revisions to the ATX12V Power Supply Design Guide V 2.2 have continued to increase the efficiency recommendations for PC switching mode power supplies and now lists both required and recommended minimum efficiencies.
We measured the AC power input to the Corsair CS850M PSU with an Extech power analyzer while the total DC load was found by adding all the individual +3.3V, +5V, +12V, -12V and +5VSB loads together.
The overall efficiency of the CS Series Modular 850W power supply is very good and easily meets the criteria for 80Plus Gold certification, even while operating on 115 VAC and at elevated, real-world temperatures – well done.
80 Plus Program
Note 1: Power Factor =0.90 (50% to 100% Load)
Note 2: Tests conducted at room temperature (25°C)
Differential Temperature and Noise Levels
To simulate a demanding environment, some of the warm exhaust air from the PSU under test is recirculated back to the intake through a passive air duct, which allows the PSU air inlet temperature to increase with load, up to 40°C.
The differential temperature across the power supply was calculated by subtracting the internal case air temperature (T in) from the temperature of the warm exhaust air flowing out the back of the power supply (T out).
Thermocouples were placed at the air inlet and exhaust outlet. The ambient room air temperature was 23ºC (74ºF) +/- 0.5ºC during testing.
T out = temperature of air exhausting from power supply
T in = temperature of air entering power supply
Delta T = T out – T in
Sound pressure level readings were taken 3’ away from the rear of the case in an otherwise quiet room. The ambient noise level was ~27 dBA.
The Corsair CS850M PSU is very quiet, virtually silent at low to mid power levels. At full load the fan noise became noticeable but not subjectively loud. I was not able to take SPL measurements at full load due to all of the DC programmable load fans cycling on and off.
(Courtesy of Corsair)
CS units were always very
CS units were always very unreliable crap, even considering that they’re cheaper. The price-to-performance-to-reliability balance is just way off in these. If you need a truly high quality PSU from Corsair exactly, and for reasonable money, get HX line AT THE VERY LEAST, NOT the CS line. If you’re on a very small and/or tight budget you can get TX or RM units just fine, but for all sakes, I’m warning you, DO not buy CS units. They really suck some major rat’s ass, big time. If you want to spend little and get a decent unit, it’s either TX or RM, if you want a perfect high tier unit for reasonable price – HX, and if you want best of the best – AX (NOT an AXi, but the good ol’ AX).
Corsair built up a great
Corsair built up a great reputation in Power Supplies,
By primarily using SEASONIC units……………..
They have now moved to CHEAPER suppliers in their low
to mid range—MOAR profits-Don’t buy them……..
Corsair high end are good products-But why bother-
Just buy SEASONIC-You know your getting quality
components and quality built-Remember the PSU is the
most important part of your build……………..
Naive and uninformed folks
Naive and uninformed folks here.
The CS line looks to me like
The CS line looks to me like it is the CX series, just “Gold” certified. Or is that over simplifying this?
So instead of actually
So instead of actually reading the review…. 🙁
Warranty period is a good
Warranty period is a good hint. Well, it works for me.
It’s not CWT. You can see the
It’s not CWT. You can see the mark “GW-ATX850SLA” on the DC-to-DC secondary board. GW means Great Wall. And all other CS units are also made by Great Wall. RealHardTechX is agree with me 🙂
Correct. It is Great Wall.
Correct. It is Great Wall. Which, in many cases, is a step up from CWT.