HD 6870 Graphics Card for a Dell XPS 420 with 425 watts PSU. Do I need a new PSU? If so, how many watts?
What CPU are you running?
How much RAM do you currently have?
How many Hard Drives/Solid State Drives do you have?
How many Optical (CD/DVD/BluRay) Drives do you have?
Do you know the brand name of the PSU that you have?
PCI Express® based PC is required with one X16 lane graphics slot available on the motherboard
500 Watt or greater power supply with two 75W 6-pin PCI Express® power connectors recommended (600 Watt and four 6-pin connectors for AMD CrossFireX™ technology in dual mode)
Certified power supplies are recommended. Refer to http://ati.amd.com/certifiedPSU for a list of Certified products
Minimum 1GB of system memory
Installation software requires CD-ROM drive, a keyboard, a mouse, and a display
DVD playback requires DVD drive and a DVD
Blu-ray™ playback requires Blu-ray drive and a Blu-ray disc
For an AMD CrossFireX™ system, a second AMD Radeon™ HD 6800 Series Graphics card, an AMD CrossFireX™ Ready motherboard and one AMD CrossFireX™ Bridge Interconnect cable is required
Copied directly from http://www.amd.com/us/products/desktop/graphics/amd-rad...