Radeon 3850 Fan Switches Off in Vista

[benz]

Be grateful if anyone has an idea on this one ?

I have an HP XW4400 Workstation running Vista64. I have had a Radeon 3850 PCI-E installed for around a week. This morning, around 3-5 minutes after cold boot, the fan on the graphics card switched-off. I immediately opened the unit up and confirmed the fan was motionless but everything was working normally [Vista Desktop, etc.].

I immeditely rebooted, and the fan switched-off again after 3-5 minutes [the PC was idle]. I have reseated all components and used system restore and the machine has now been running for 3 hours without any problems.

The fan is mechanically and physically fine and the PC and graphics card appear to be functioning fine. I am not using any utilities or fan-control or overclocking, etc. I am using the latest Cataylst set from ATi [driver only, haven't installed control panel].

Slightly baffled ? Anyone had this before ?

[Rosaline]

Where you actually doing anything that required heavy graphics card load at the same time, or was this just whilst casually using the computer (but not playing games, etc)?

[benz]

Thanks for responding. No graphics load other than the Aero desktop. The first boot the machine only had Windows mail open and on the second boot no applications were open. The only configuration change to the machine yesterday was installation of Vista ActiveSync for mobile devices [I plugged a windows mobile in for the first time]. This has now been removed as a result of system restore.

[ackrite26]

Try playing a game and see if the fan starts to spin then.

[MadduckUK]

Try playing a game and see if the fan starts to spin then.

and see what temps its getting to in CCC

[benz]

Thanks guys. If it cuts out tonight.... I'll try HL2 and keep a close eye on temps as you suggest. I am just puzzled as to what could cause such a specific and isolated problem.

[aidanjt]

It's normal. The drivers shut off the fan (or slow it down to an inaudible level) when the GPU is cooler than an eskimos dangly bits, i.e. when you're not running a 3D app. AMD GPUs just run that cold that they can do without the fan when they're idle(ish). You might notice it spin up if you do mad/random window manipulations with Aero for a few minutes, try opening 50 instances of notepad, and throw in a few media players playing something and alt+tab like mad, use switch 3d too.

[benz]

UPDATE: I have done some testing and you are all absoutely right, this seems to be a design feature of the card. I never imagined it could be that power efficient [esp. as the single slot cooling version].

Thanks to everyone.