XFX XPS-850W Power Supply Reviewpaulktreg -
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No foam! The XFX Black Edition 850W is the only power supply I have tested so far (I think), that doesn't use any foam inserts to protect the power supply. The base of the power supply is only protected by two layers of thick cardboard, which could make it vulnerable to transit damage, especially if shipped in the original box. However, I think this is very unlikely and it would have to be heavy blunt force trauma to cause serious damage. The fan side of the power supply is shielded by the modular cable box, which is as good as any foam layer, and the sides by sturdy cardboard inserts that give a good buffer zone and reasonable protection. The modular cable bag is probably one of the best I've seen, if you like that sort of thing, but is it really necessary? In most cases I would argue that once the power supply is installed and fired up the cable bag is thrown to the back of the cupboard to rarely be seen again, if at all. Combine the recyclable packaging with great efficiency and the XFX Black Edition 850W power supply earns a few more green points than most other units I have reviewed.
Price Per the Watt:
Power Supply XFX Black Edition 850W at $199.99 = $0.23/Watt (September 2009)
The XFX Black Edition 850W does have a look all its own, with its industrial-themed case and lime green fan, which I feel will surely appeal to some people – but performance must come first. The XFX Black Edition 850W didn't really put a wrong foot forward, but what it didn't do, following the OCC testing methodology, is meet the requirements of its claimed 80 Plus Silver certification. The standard requires an efficiency of 85%, 88% and 85% at 20%, 50% and 100% loading, respectively. The XFX 850W just failed at 50%, actually loaded to 49%, on 110VAC with an efficiency that was rounded up to 87%. I could not load the power supply to exactly 50% and combined with test equipment measurement inaccuracies of up to ±2%, that must be taken into account. As such, it is a minor failure that can perhaps be overlooked. I would however like to mention the 80 Plus certification for the XFX Black Edition 850W, which shows the unit passing with an efficiency of 88.1% (very close to the minimum requirement of 88%) and I really cannot see the manufacturer getting the necessary consistency on the production line to meet the 80 Plus Silver level with every unit, but maybe I'm wrong?
Cast your eyes back to page three and the cable length table. The peripheral and SATA cables are supplied in three different lengths – a nice touch, which may go a little way to helping with cable management and that uncluttered look. One small bone of contention is a Mean Time Before Failure (MTBF) figure of 100,000 hours quoted at 25°C. This temperature is totally unrealistic, especially if the power supply is heavily loaded. Most power supplies will easily reach a working temperature of 40°C and rise to 50°C if pushed, so come on XFX, let's see a little more confidence shown in your products.
Putting the 80 Plus Silver issues aside, the XFX Black Edition 850W performed admirably. The DC voltage load regulation was excellent, DC quality well within specification, and excellent efficiency of up to 89%. If you are in the market for a power supply to run any high end system with graphics cards in an SLI or Crossfire configuration, then I have no hesitation in highly recommending the XFX Black Edition 850W power supply. Heck, if you like the looks, then fit one in your system anyway – not that you'll see it in most enclosures!
- Excellent DC voltage load regulation
- Good DC quality
- High efficiency
- 5 year XFX limited warranty
- Marginally failed to meet 80 Plus Silver (following the OCC testing methodology)
- MTBF figure quoted at 25°C