I also have a weak (300w, 18a), aging power supply that came in my Compaq that I purchased in late 2004. It originally had a P4 w/onboard VGA (Intel GMA 900). I gutted it and replaced the P4/mobo with an OC'd Opteron 165/Biostar 6100. I'm also using 4 sticks of ram vs. the two it came with. I then added a 7600gt. I only have one SATA HD and one DVD/RW connected.
So far, it hasn't had a hiccup, even after 3 hours of gaming.
I too purchased the card for it's dual head to use for video editing. I hooked it up to both monitors and it worked fine. But I need a new case for cooling (I currently have the door off) and a new PSU before I install the other SATA for video editing.
To the PSU guru's, what will happen when/if my PSU gives up? Will there be any warning signs? Will the PC just turn off / not turn on? Can it kill a component or two?
What's the best value PSU for my current set-up + another DVD/RW and SATA HDD? How about with an 8800gts 320mb as I'll probably upgrade later this year.
Would these do fine?
http://www.newegg.com/Product/Product.aspx?Item=N82E16817256008
http://www.newegg.com/Product/Product.aspx?Item=N82E16817104034
http://www.newegg.com/Product/Product.aspx?Item=N82E16817104934
http://www.newegg.com/Product/Product.aspx?Item=N82E16817104037