I recently picked up a Sapphire 7770 (non overclocked version) and the card's running wonderfully...except for one "minor" problem.
Whenever the system goes idle and the monitor does an auto-shut off, a few minutes later, the card will start making a distinct and noticeable "click" sort of grinding noise. It sounds like something inside the case is hitting the fan for a split second and stopping. I've double checked this and nothing is actually even remotely close to hitting the fan.
Does anyone have any sort of experience with this? It doesn't cause a problem when I come back to the computer...usually. It seems the longer the system has sat idle the more likely it is that the card doesn't start back up when I come back.
My money would be on a loose fan. I had a pair of 5870's from sapphire up until last week. One of the cards had that same problem. When I went to replace them I checked them both over carefully and found that the fan on one of the cards was loose. This was causing it to spin unbalanced. It was way louder in idle than it was under load. slicedtoad has it right, if it's under warranty send it back. Sapphire also has a 2 year warranty, you can get the information from their website but you'll need the original purchase information from newegg in order to get it.
^only problem with Sapphire is they make you pay for shipping to and from hong-kong usually. I usually fix my own sapphire cards instead of sending to them if possible. But then i'm in Canada, it might be cheaper from the US.
Just an update for future reference and to maybe archive this for Google.
After returning the card and getting a new one, I was having the same problem. After going through and doublechecking, I eliminated my PSU, mobo, and the card itself being the cause of it, which left me completely stumped.
A little bit more research and a lucky Google search revealed the problem: ATI cards are shipping with a feature called "Zero Core" now (zerocore) that for some people are causing Windows to stop recognizing the card when it powers down. It's supposed to power down the fan and turn the card into a near-off state, but for some people, it causes Windows to think the card's not there anymore and will hang the system when it comes out of sleep mode. It's an issue with the Catalyst drivers at the minute.
I appreciate all the help from everyone, thank you.
The same thing's happening to me too. The card's fan doesn't stop completely, but goes into a kind of low-RPM mode. I think it's supposed to stop spinning completely, and sometimes it does, but sometimes it goes into a kind of weird low-RPM mode, where it doesn't spin at a constant rate, but in a kind of pulsating one. I stopped it with my finger and I can feel a pulse from it every 5-10 seconds. You can also see it; when the fan receives a power pulse, it increases its speed, then starts spinning slower and slower, until it receives another pulse. Every time it receives this "pulse", it makes a whining noise. I checked, it's connected properly, and it's not actually hitting anything. It must be defective. I'm thinking if I should have the card replaced, or just keep it. Setting a custom fan mode with Sapphire TRIXX might fix the issue, but I haven't tried that yet.