I haven't had that problem but thanks for the information. I'll probably build my own computer from scratch next time and keep this cooling approach in mind. The only issue I had was the screen sometimes did not come back on after coming out of sleep mode. It was right after one of the major Windows updates and I finally figured out that maybe the driver was flaky. Updated the driver and no more problems.
Many people don't notice the fan rattle because the rattle is less loud than their power supply or system fans. I take a small amount of pride in building PC's that you can't hear even if setting on the desktop (and not the floor) in front of you. The last one I built is here
, unfortunately I was unable to use an Arctic Cooler on the 5770 because it was a very small case using a MATX board and there just wasn't enough space after installing the OCZ PCIe Revo Drive.. Yet its so quiet, setting on the desktop in front of you, the video card fan is the loudest thing you hear.. it's very soft, but if it started rattling it would become very annoying. The worse ATI fans that rattle are on the 5880/5970 and their 6000 series counterparts. After a month or two the bearing develops play and the rattle begins.
The 5770 doesn't run hot unless under load, but check it out in the ATI Overdrive part of your software. With an Arctic Cooler you can get it to idle at ambient temps, and not rise above 70-75c during full load.. and that would be rare. They're cheap and easy to install and the gains are very real.. so I'll always add one if I can.