Of course, Linux users have to be concerned when buying a recent model computer whether there are hardware drivers yet for Linux. AMD now (late March 2012) has a very nice Linux driver developed for their Radeon GPUs, Catalyst 12.4, and it works fine with the A8-3820/HD 6550D in this HP p7-1220 computer. Presumably, you could install this driver yourself, but I'm using the version in Ubuntu 12.04 (to be released in April 2012). I don't do computer games, so I can't tell you about graphic performance for games, but I think it should work well -- at any rate, for just handling an ordinary desktop, I'm very pleased with the graphics.
Linux also handles all the other hardware here that I use: hard disk, wired ethernet, wifi, usb 2.0, SDHC reader. I haven't tested Bluetooth. I had a small issue booting up from an early distribution DVD for Ubuntu. In case the problem hasn't been fixed, I'll tell you how to do it: interrupt the HP boot sequence with the ESC key to get an HP menu, go to the boot submenu, and choose the "legacy atapi" cdrom boot up. Then, it works.
I'm using a previously bought keyboard and mouse, so I can't tell you about the ones supplied. I experimented only briefly with hooking up two monitors, and that worked, but I haven't gotten around to trying anything useful with that arrangement.
I added a 2TB hard disk, using the empty slot available in the internal cage. That was easy, following an illustrated step-by-step guide that HP provides on its web site. Look for "How to HP Pavilion p7-1220 Desktop PC" > "Adding / Replacing hardware". I had to buy a SATA cable.
I've had this for 2 1/2 months, now. I don't hear any noise from it at all.
Nice computer. Good deal.