MP 7,1 GPU Fan Issue

[Dolphins1972]

Ugggh... Can't open case to see if fans are working so I would have to somehow manually test each GPU in another machine.

For reference, the RX 6900 XT when in slot 1 covers slot 2 and the same for slot 3 and 4.

GPU fans don't spin when monitor is plugged into GPU in slot 3.

But when monitor is plugged into GPU in slot 1 the fans on GPU in slot 1 come on around the 150F mark.


Even if GPU in slot 3 is defective, the fans on slot 1 GPU should still work, right?

 

[mattspace]

• swap the gpus in their slots - what happens?
• Run a multi-gpu-aware gpu-stressing workload that loads up both gpus - what happens?

 

[ArtRev]

I’ve removed the slot covers above each GPU. The fans on the 6900XT start spinning when the temperature exceeds around 65°C. Under heavy load and extended use in my system, the cards reach about 98°C. The Mac’s fan starts ramping up significantly around 94°C. The 6900XT cards run quite hot, but according to AMD, their safe core temperature is as high as 108°C or 110°C.

Additionally, in my opinion, the temperatures shown by iStat aren’t accurate—I read about this somewhere.

 

[Rimmsi]

RX 6900 XT cards use so called semi-passive fan regulation, they are turned off up to 65°C, when this temperature is exceeded, they spin at about 700rpm, MacOS does not allow displaying the temperature and correct speeds on these cards.

 

[Dolphins1972]

RX 6900 XT cards use so called semi-passive fan regulation, they are turned off up to 65°C, when this temperature is exceeded, they spin at about 700rpm, MacOS does not allow displaying the temperature and correct speeds on these cards.

Can you elaborate? I want to make sure both GPUs are fully functional.

 

[Dolphins1972]

• swap the gpus in their slots - what happens?
• Run a multi-gpu-aware gpu-stressing workload that loads up both gpus - what happens?

Yes, I have plans to do so, but have not yet. Do you have any suggestions on a multi-gpu test?

 

[Dolphins1972]

Okay, swapped slots and viola. Must have been loose cabling that I missed?






I reused the Lego's from the previous owner in between GPUs.

 

[Dolphins1972]

I did some digging on a temp monitor for AMD Radeons in MacOS. I have no reason to believe iStatMenu is reporting falsely. Apple continues to alienate itself from competitors by dropping support for third party hardware/software that they once supported. Fortunately there are workarounds by injecting kext. RadeonSensor is a free tool: https://github.com/aluveitie/RadeonSensor