I would have concluded it was the fan but the sound is not coming from the fan but from beneath the heatsink, on the 8800 the fan is offset from the core a bit, it's closer to the back end of the card rather than sitting on top of the core, and the sound is coming from the xact spot where the core is, so i'm led to believe the fan on the 7900 isn't @ fault either, since it's not just one card exihibiting these symptoms and My 7900 is in a pretty tight fit in my XP machine, the fan only has a couple mm of clearance from the tv tuner, so it always runs@ top speed under load and i never heard this sound under Xp, unless i was brutally oc'ing a card and it needed to be backed down. (I had a GB 7900GT that would make that noise whenever i went a little too far with the coreclock and ran a game or bench, i clocked the core from 535 to 635, it would stay stable up to 645 but 1mhz higher than 635 and i'd hear the same sound i hear now under vista with both my cards.)
The funniest thing though, going into the power settings in vista and turning on PCI-e link ASPM to at least moderate power savings, kills the sound(And chokes the card too?), so i'm thinking that without link power management vista can't control the flow of power to the card properly (Could be an ultimate only problem? since other versions may or may not have the ability to affect the power settings?)it's the only logical explanation i can come to after all the tests and troubleshooting i've done over the last few months. i'm hoping M$ possibly identifies this issue and tries to make some sense of it.
The funniest thing though, going into the power settings in vista and turning on PCI-e link ASPM to at least moderate power savings, kills the sound(And chokes the card too?), so i'm thinking that without link power management vista can't control the flow of power to the card properly (Could be an ultimate only problem? since other versions may or may not have the ability to affect the power settings?)it's the only logical explanation i can come to after all the tests and troubleshooting i've done over the last few months. i'm hoping M$ possibly identifies this issue and tries to make some sense of it.
