PS. Let me guess...these came from eBay ? ?
No. These came directly from newegg.com.
Of course it could be the MBoard as well...but unlikely if you've installed them into different rigs...
No, it's not the motherboards because I had the comps running for a while without the graphics cards and there was no noise.
Return the cards under Warranty...this is not normal behaviour.
I think I am going to wait until I see some problems because they perform very well and don't make that noise when they are running. It seems unlikely that all three would be bad.
Does any one have a geforce gt 240? Have you ever heard this noise? It's about three minutes after you power off the system.
Something just occured to me. Wouldn't that be the time when the capacitors are discharging? Do caps ever make noise when they discharge?