Athena Power AP-RRP4ATX6508 80 PLUS Certified 20+4Pin 2 x 500W Mini Redundant Server Power Supply

Pros: -80+ unit for this price
-Active PFC
-Solid construction (it's very heavy, no bulging caps)
-Output tested within specifications
-Tolerates single module failure with no voltage drop
-Great service (see other thoughts)

Cons: -Difficult to mount in some chassis (put this in first)
-Does not come with documentation
-Runs a bit too loud for anything but the server room

Overall Review: Overall I'm very impressed with this unit. Output tested almost dead on with the supplied specs. The packaging didn't come with a manual, but I contacted Athena support and they were happy to provide me with relevant (if a little sparse) documentation. I did have a module fail on me, but the server continued to run fine on just one module. I sent an email to Athena and they called me within 15 minutes, agreed to cross ship the module (shipped out the same day!), and updated my account to allow for one more module RMA within the 3 year warranty period. I've had units from Supermicro and others fail as well, but never received anything like decent support. This is just something that happens with power supplies (otherwise why would anyone purchase a redundant supply in the first place). The features for the price and outstanding customer service are what set this unit apart. I was so impressed that I'm now planning to deploy several more of these for a new virtualization project.

Pros: It is a 500W redundant, 80 PLUS certified power supply.

Cons: When I measured it myself, I found that the actual dimensions were closer to 6" x 3.25" than the Mini Redundant standard 5.91" x 3.31" which made it difficult to get this thing to fit properly in my 4U case. I wound up having to jury rig it by cutting out foam from the packaging to serve as spacers.

Overall Review: Newegg needs to include the Power Supply Form Factor as a parameter for both Power Supplies and cases. As it is now, you have to go to the case manufacturer website to find what power supply form factors are compatible with a case. Ideally, they'd also run a shopping cart check to make sure your power supply and case are actually compatible, but that would be mostly for first-time server builders like myself.