This is my model: Gateway 825GM - ( http://support.gateway.com/s/PC/R/4364/4364cl2.shtml ) P4 3.4Ghz ( 550 Chip ) 2GB Ram 250 SATA 7200RPM HD D915GSN: BTX Form Factor Motherboard 16X DVD-ROM 16X DVD+RW Dual Layer Integrated Sound Integrated 10/100/1000 NIC 7 USB 2.0 Ports ( 4 used ) 1 IEEE1394 Port ATI Radeon X300 SE ( PCI Express 16 ) 128MB Video < --------- 300 Watt Power Supply <-------- My question is about the two arrows above. I want to upgrade to either an ATI X700 Pro or a nVidia 6600GT Video card as the ATI X300SE is the most basic PCIE card there is and acts like it. After a bunch of research i've pretty much figured out that my 300watt is not going to cut it. I bought a 500watt power supply from Gateway ( the maker of the PC ) after consulting with them and assured it would work..... it didn't. It had to be returned. My question(s) are..... What power-supply will do the job? and do I really need to upgrade the power- supply to get this card? Ohhhh and one other question.... My DVD+RW is the Master and the ROM is the slave... will I get any performance boost if I reverse this? ( SATA HD is on a different channel ). I am on a budget so anything over $225 including a new Power-Supply is simply out of the question. I am not a Serious Gamer but I do like to play some graphic-intensive games from time to time ( Splinter-Cell, GTA3, GTA Vice-City and soon GTA San Andreas ).