I'm in a similar boat (Ti4400 with fan being the noisiest thing in my rig) and while I've considered getting a heatpipe cooler, I've decided to go another route. The cheapest I could find a ZM-80D was around $40 shipped. Instead of spending my money on that, I figure I'll credit that towards say a 9600 XT from Newegg, and I'm only paying $100 to upgrade my Ti4400 to a DX9 card. (Yes, that's somewhat fuzzy math -- but in the end it all balances out.)