New Mac Pro gets windy with 2008MP's graphics cards!

[npj]

Hi all!

I've googled for a good hour trying to find a fix and have had no luck...

I've got 2 Mac Pros (an early 2008, and a 2009 I've just received).

My new MP has one of these - NVIDIA GeForce GT 120

The 2008 MP has this - NVIDIA GeForce 8800 GT 512MB - and this - ATI Radeon HD 2600 XT 256MB.

So, for practical reasons, I need to swap these graphics cards between the two MPs. All are PCIe cards so I thought it would be problem free...

With the GT120 that came with the new MP, the expansion slot fan goes at a calm 700rpm. If I have both or just one of the two cards from the 2008 MP in the new MP, the expansion slot fan (after a couple of mins) slowly revs up to about 1700rpm. It's pretty loud. Something's definitely not right.

I would expect the expansion slot fan to run a bit high from having bigger, hotter card(s) but this seems a bit extreme. The fan's easily too loud to live with.

This is also the 2nd 2009MP if had - I returned the first machine because of a sizzling power supply. Both of these 2009MPs had this graphics card problem.

Any help would be great.

npj

 

[lemonade-maker]

I had the same issue with a gt120 and a 8800gt in my 2009 macpro. pci fan ran at the same speed and the 8800gt fan was crazy loud. I replaced the fan/heatsink with an arctic passive one and things calmed down. The pci fan now runs at 900 rpm. Pretty quiet system except for the 5x1.5tb drives.

 

[npj]

Right... Are you talking about the fan in the Mac Pro (expansion slot fan) or the fan built into the PCIe card(s)?

I don't know if I want to go messing around with modifying things. I'm not too experienced in the area. I've asked about this on macosx.com and they thought the problem was that the 2009MP has a newer chipset/firmware for driving the PCIe cards that is incompatible with the older cards. They also found in the MP's manual: "Important: Graphics cards from previous Power Mac G5 and Mac Pro models are not software-compatible with Mac Pro (Early 2009) models." - Bummer