Strange ATI 5770 fan issue

[jenzjen]

Bought an Apple 5770 to install alongside my 5870, installed it and running on both Lion and W7 with no abnormal fan issue, completely quiet. All software was fully updated.

Here's where it got weird. Then, I upgraded to an Intel 330 SSD to replace my X25, but no matter what I tried (PRAM, SMC resets, updated ATI drivers, etc) the 5770 fan would blow hard under both Lion and W7 with machine just idle, nothing open. This was a clean install of both OSs on the SSD.

So, then I put the X25 back in, 5770 fan back to completely quiet. Just for kicks, clean erased the X25 and clean reinstalled both OSs (just like I did on the 330) and fans still staying completely quiet.

Any ideas why? Just a fluke issue on the 330 install?

 

[BigJohno]

Bought an Apple 5770 to install alongside my 5870, installed it and running on both Lion and W7 with no abnormal fan issue, completely quiet. All software was fully updated.

Here's where it got weird. Then, I upgraded to an Intel 330 SSD to replace my X25, but no matter what I tried (PRAM, SMC resets, updated ATI drivers, etc) the 5770 fan would blow hard under both Lion and W7 with machine just idle, nothing open. This was a clean install of both OSs on the SSD.

So, then I put the X25 back in, 5770 fan back to completely quiet. Just for kicks, clean erased the X25 and clean reinstalled both OSs (just like I did on the 330) and fans still staying completely quiet.

Any ideas why? Just a fluke issue on the 330 install?

Try installing MSI afterburner on windows and then change the fan from auto to user. Then turn it down and restart into osx... I don't know if this will help but it's worth a shot.

Im thinking of getting a 5870 to run along with my 5770. use the 5870 on my main display and 5770 for my external. Have you stressed the power on the cards? Are you splitting the power between them off the main board?

 

[jenzjen]

I have not tested the power levels since there's a lot of others who installed both 5770/5870 on a stock Mac Pro with no need for additional power - I just used a Y splitter to create a 3rd 6pin connection for the 5770.

2 5870s, IIRC, do require an additional power source.

 

[jenzjen]

Update for others - fixed the issue - it was the brightness setting. Turning it up too far = MP fan starts to blow, not the 5770 fan.

No issue at all with the 2 cards and 3 ACDs now.