I bought 2 of these and one ran like a scolded ape, and the other dragged. I worked on the slow one for a few hours changing HD's and checking the BIOS.  I finally restored the BIOS to factory spec's and that is when I learned of my troubles.  They gave me a Power Supply that wasn't rated for this system, and you can turn off the warning in the BIOS.  I changed the PS with another one I had and it ran like a scolded ape.  If you buy one, check the PS and make sure it has the right wattage otherwise it will crawl.