ok, first post here ... so be gentle.
i've read through most of this thread fairly carefully, and there is definitely 2 different trains of thought when it comes to the power needs of these cards.
here's my system specs, and experiences with my card (His x1950 Pro Turbo v2 - AGP)
Athlon64 +3700 (754 skt)
Arctic Freezer 64 Pro cooler
Gigabyte GA-K8NSNXP
4 Seagate 16mb cache drives (2xSATA 2xIDE)
1 more Seagate IDE drive in a icy-dock removable caddy
Plextor 716SA
Plextor 608AL
NEC 7543A
HiS x1950 Pro - AGP
PSU - Corsair 620W
Monito DELL 2707wfp
I purchased the x1950 v2 from overclockers uk some time ago, and initially had no problems, at the time i was running an Antec Neo HE500 PSU, then within 3 weeks poof! no more switch on, no warning nothing, worked fine on shut down, at the time i was doing some cleaning in the case, and re-seating the RAM afterwards, so i figured i'd pressed to hard and killed something on the mobo, so after swapping everything out and still getting no boot i replaced the mobo, still nothing, the only thing i could think of was that the PSU was dead - but i had tested with another and nothing else connected and it still didnt work, so i took the plunge and ordered a new PSU as i had no way to fully test the old one, turns out that was the problem, and the 380W generic i had tested it with was not even man enough to boot the pc with this card in it !!
Dabs replaced the PSU no problem, it was still within the warranty ... just, and had ran all that time with no problems.
when searching for a replacement i did the research on the requirements and was also surprised to read the amperage requirements for the card, and wondered if that had contributed to the PSU's early demise. I settled on the Corsair unit for a number of reasons, including it's tested stability, power consumption, and it's ability to behave like a single rail unit if overloaded on one of the rails. At the time i did not have the money for a PC P&C unit.
This Corsair unit has run flawlessly in my system now for a few months, and the card is running perfectly, a little warmer than i would like but still good, no artifacts and plays movies very very well, driving the 27" LCD very nicely at 1920x1200
so - did the x1950 help to the early demise of the PSU - possibly, but i guess i'll never know for sure, but i am looking to replace the Corsair with a PC P&C Silencer 750 shortly with a planned upgrade because i dont like it's cooling configuration in the Antec case layout (which i'm about to swap for a P182)