Dual CPU 4,1 replacement tray - fast spinning fans

[MVMNT]

So, admittedly, I took a bit of a punt on a dual board from eBay for a Dual CPU tray for my 4,1>5,1 flashed Mac Pro. Eager already on the upgrades I know, but this was a bargain to not try.

I did a visual check, and it was a 2009 board - there really is a visual way to tell the difference in photos - and the seller told me it was from a 2009 Mac, but the listing also stated that the fans ran at high speed constantly and were throttled with Fan Control.

OK, I thought, definitely a 4,1 board... maybe he's been using it in a 5,1? Then considering the mere possibility I had a real bargain on my hands.

Just received it, and lo and behold, the fans do run fast... BUT it's also a 4,1 board. Both the SMCs are 1.39f5...

So next steps, I'm throwing out there to you all. Anyone come across this before? A matched 4,1 board running the fans fast? Is it a bug? The seller had taken it in to Apple and they passed it off as not being something to harm the machine.

If it can be fixed, great, I'll owe someone a virtual beer.

 

[TheIguana]

Are both processors installed and running okay? One of those being out of whack seems to be a common cause of fast running fans for folks that do a CPU upgrade.

 

[MVMNT]

Are both processors installed and running okay? One of those being out of whack seems to be a common cause of fast running fans for folks that do a CPU upgrade.

They're - what I assume to be - stock dual core CPUs being 2.26's. Maybe one's gone awry.

 

[h9826790]

So, admittedly, I took a bit of a punt on a dual board from eBay for a Dual CPU tray for my 4,1>5,1 flashed Mac Pro. Eager already on the upgrades I know, but this was a bargain to not try.

I did a visual check, and it was a 2009 board - there really is a visual way to tell the difference in photos - and the seller told me it was from a 2009 Mac, but the listing also stated that the fans ran at high speed constantly and were throttled with Fan Control.

OK, I thought, definitely a 4,1 board... maybe he's been using it in a 5,1? Then considering the mere possibility I had a real bargain on my hands.

Just received it, and lo and behold, the fans do run fast... BUT it's also a 4,1 board. Both the SMCs are 1.39f5...

So next steps, I'm throwing out there to you all. Anyone come across this before? A matched 4,1 board running the fans fast? Is it a bug? The seller had taken it in to Apple and they passed it off as not being something to harm the machine.

If it can be fixed, great, I'll owe someone a virtual beer.

Could be sensor failure. Any overheating indication (including false reading) may cause the fans spin at full speed, but will be able to spin down by altering the target fan speed (e.g. via MacsFanControl)

 

[MVMNT]

Swapped my Single processor back in, then out again. Rest the SMC (I think) zapped the PRAM. It seems to be behaving a lot more than first install... It went ballistic even opening up System Profiler.

PRAM rest has messed my CUDA drivers up though. Was able to restart back to the Nvidia drivers as it's an EFI card. Still appears to be behaving.
[doublepost=1550100466][/doublepost]Added my 32GB across form the other tray, and it's started up again. But not immediately. CPU temps look ok in MacsFanControl too. It's just BOOSTA and BOOSTB going like the clappers.

 

[MIKX]

I replaced my 4,1>5,1's dual 2.93Ghz tray last year _ 32gb ECC ram for about US$500 last year. No problems so far.

 

[leon771]

Delete. Didn’t read OP properly.