Exclusive: Antec Signature 850W
by Christoph Katzer on May 7, 2008 2:00 AM EST- Posted in
- Cases/Cooling/PSUs
Efficiency
![](https://images.anandtech.com/reviews/psu/2008/antecsignature/eff.png)
![](https://images.anandtech.com/reviews/psu/2008/antecsignature/eff-comparison.png)
The Signature 850W power supply has great efficiency and it tops most recently tested units, especially with lower input voltages. 87% efficiency with 230VAC is very good and it even stays that high for quite a bit. With 100% and 110% loads, it maintains the same efficiency even though we normally see a significant drop at this point.
There is a reason why this unit has the Bronze 80Plus certification: with 120VAC it still reaches up to 85% efficiency and even stays above 82% most of the time. It can even reach higher grounds with only 90VAC and makes it up to 83% at around 400W. As the graphs show, users of this unit should have at least 150W of continuous power draw; otherwise, it is just not working efficiently enough. With an average power of 300W onwards this unit will have its perfect working environment.
Power Factor Correction
![](https://images.anandtech.com/reviews/psu/2008/antecsignature/pfc.png)
The power factor correction is one of the best we have seen to date. At lower input voltages we see a constant high level that is just not possible, presently, to better. Even Europe can build on a good correction at lower power draw.
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JarredWalton - Wednesday, May 7, 2008 - link
I have used dozens of Antec cases over the years... I have not yet purchased an Antec PSU separate from a case, however. Then again, Earthwatts might make that a reasonable thing to do these days.strikeback03 - Wednesday, May 7, 2008 - link
I've used EarthWatts 380 units in a couple of systems for the lab. Seem to do fine, nice and quiet, and prices around $20-30 after rebate at Newegg, works for me.DDG - Wednesday, May 7, 2008 - link
I recently picked up the Earthwatts 650 unit and I must say I'm impressed so far. It's quiet and has 6 SATA and Molex connectors as well as 2 PCI-Express (1 6-pin and 1 6+2 pin). It replaced a Truepower 550-watt PSU that was 5 years old but still going strong (just too noisy and not energy efficient).