I have an H8-1010T (HPE) Desktop computer, I just ordered an ATI 6850 Graphics card... the PSU in my desktop is only 300 watts... i have no extra perriphials plugged it (no extra hard drives, optical drives, etc) am i going to need to upgrade this? i don't plan on overclocking it.
depends, is your psu of quality, and has a 6 pin connector? according to This the card would eat up too much of your psus wattage on load. and that would be pushing it. unless you had an EXTREMELY high quality psu that can push past its labled wattage, you are going to need a new one.
if your planning to no overclocking at all and never upgrading parts in the future, get a 380-430w certified psu(I emphasize the word certified, preferably bronze at the least, common choice would be an antec earthwatts for low wattage and works well)