I want to upgrade my PC because I want to dual boot Windows 7 with a Linux distribution and play basic gaming on my PC. I need to to know if these: Western Digital Caviar Black WD6401AALS 640GB 7200 RPM 32MB Cache SATA 3.0Gb/s 3.5 internal HDD and a Radeon HD 4850 or 4670 are going to be compatible with my Dell Dimension E520 with a 305 watt power supply already running a Pentium 4 HT 3.00GHz, Integrated Intel G965 Express Chipset Family GPU, Dell 0WG864 motherboard, 80GB HDD, DVD/CD-RW Drive, 3GB Memory.
I have the XFX Radeon HD 4770. It's a good mid-level general purpose card and it does not use very much power. It's only 8.5 inches long and requires only one 6 pin PCIe power connection. Technical reviews have been very favorable and Tom's hardware did an article about using two of the cards in Crossfire mode. You just have to remember it is not a high end gaming card.
I am convinced that a 4670 and a 4770 could run on my PC, but I went to PNY's site to check for system requirements for the 9800 GT EE and I found out I need a 400 watt or more PSU. Will this be a problem?