A few months ago, I decided that my 5 year old desktop needs to be updated. First I reformatted my hdd and installed win7 ultimite 64 bit to replace the 32 bit broken xp media center that kept crashing. Then I added 2x512mb ram to my 2x1gb filling all the slots. I also got an ati hd 5770 to replace my motherboard's "graphics accelarator" . When I asked on a few forums about the power requirements of the 5770, everyone told me to get a new psu because my current one is a 300w hp power supply that came with my pc. I dont like shutting it down so it usually runs 24 7 unless I have to reboot to install something so I guess that my psu became 250w or something for running so long. So I Just plugged it the graphics card and connected it with a 2x 4pin molex to 6pin 12v cable. I was going to get a new power supply in a few days but I kept slacking untill the weeks became months but my pc was still stable . I never ran any stress testing because I am afraid that it will fry my psu but I was able to overclock my graphics card from 850 to 900 mhz and run it for a few days continuously at 100%. So do you think I really need a new power supply? And if I get another 300w psu, can I plug one of my 4pin molex connectors into my old one so that they share the load from my graphics card?