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Do UnFlashed/Flashed 970/980/ti Cause Expansion Fan Revs?

Thanks for taking the time to do the testing. It doesn't sound like anything turned up, though for what it's worth, my Mac Pro's idle PCI fan speed is 800 vs the 1100 you're observing. I manually bumped mine up to ~1100, and I could hear a slight difference in noise, but it was still fairly quiet (enough to qualify as "normal operation"). I imagine the discrepancy is either due to your W3690 upgrade, or due to ambient room temperature. But I suppose it could also be a clue as to why some users have trouble and others don't. Maybe higher-power/heat systems are less susceptible.
 
The W3690 won't cause the high PCIe fan idle. I have this CPU installed in my 4,1. And my PCIe fan can stay at 800RPM with 2x7950 installed (both card only connected to the 6 pin source on the mobo without any extra PSU / mod).

However, I wonder if this is "number of monitor" related. I only connect one monitor to my 4,1.

May I know how many monitor(s) you guys connected to ONE card, and your idle PCIe fan speed?
 
h9826790 said:
May I know how many monitor(s) you guys connected to ONE card, and your idle PCIe fan speed?
Click to expand...

I currently run single monitor, but I've had both single and dual monitor setups without problem. 1100rpm idle. I doubt number of monitors is related.
 
ActionableMango said:
I doubt number of monitors is related.
Click to expand...

AFAIK, some GPU will stay at a higher idle clock frequency when connect to more than one monitor. That will actually cause the card to draw more current and run warmer. Which may cause the PCIe fan stabilize at a higher idle.

Anyway, it seems not related in your case.
 
I just realized that I have an open-fan heatsink video card, not a rear blower. So the GPU heat is expelled into the PCIe area, not directly out back. This almost certainly explains the 800 vs 1100--it's just normal fan operation based on higher temps.

04G-P4-2986-KR.png
 
I doubt that the open-fan heatsink video card is responsible for the higher rpm.

I had a GTX 680 rear blower in my MP, now a open-fan heatsink GTX 770, PCI fans rpm are still 800 on idle.
 
Synchro3 said:
I doubt that the open-fan heatsink video card is responsible for the higher rpm.

I had a GTX 680 rear blower in my MP, now a open-fan heatsink GTX 770, PCI fans rpm are still 800 on idle.
Click to expand...

I think that dual processor systems that have been upgraded with 130W TDP CPUs may be more susceptible to temperature variations from video cards. Each of the CPU heatsinks in dual processor 4,1s or 5,1s are smaller than their single processor counterparts...

Of course, this is just my guess.
 
Hello, I have a MSI GTX 970 4GD5.
On my MacPro 4,1 flashed to 5,1 the PCIe Fan "sometimes" stays at 800 rpm from cold boots and never rev up even if using gpu intensive apps. (I experienced this 2 days in the last 15 days.)

Most of the time if I start a gpu intensive app like Lightroom / any Game / Unigine Heaven, the fan will rev up between 1600 and 2200 rpm and stay there forever.
Cold boots fixes pcie fan speed only until I reach desktop and log in.
SMC reset puts back PCIe Fan to ~1100 rpm.
Once in a while mac will boot with PCIe Fan @ 800 rpm.

It's so random that I'm glad Macs Fan Control exists.

EDIT: I have not upgraded cpu's yet and GT 120 is not in the MacPro anymore.
 
Last edited:
pigsyn said:
Most of the time if I start a gpu intensive app like Lightroom / any Game / Unigine Heaven, the fan will rev up between 1600 and 2200 rpm and stay there forever.
Click to expand...

When you start CUDA-Z a few seconds and quit it, the PCI fan still stays between 1600 and 2200 rpm?
 
i have cuda-z set as a login item. then i click on performance tab and check heavy work load. Wait about 5 seconds or for the fan to hit 2000rpm and then quit the app. everything settles down to 800 and never goes back up unless i stress the card real hard.
 
MP 4,1->5,1 (2009) with 3.46 gHz X5690 and a MVC-flashed 980 (a reference open-fan EVGA). I do experience the fan issue. I fix it via Mac Fans Control, so I will see the fans rev up high during boot, and after logging in Macs Fan Control settings kick in and the speeds slowly drop. They will go absolutely crazy during option-boot while selecting a different startup drive, or if I leave the login screen up after booting.
 
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