MP 1,1-5,1 CPU Tray Swap Mac Pro 4,1 to 5,1

[teameurox]

As title lists I’m trying to figure out my options here. I was able to score a dual processor cpu tray with 2 hexacores and 128gb ram for a very reasonable price. Turns out my machine is actually a 4,1 that was flashed to 5,1 it appears as when I insert the CPU tray in the machine and reset smc and nvram pram etc. i get full 100% fan ramp up and doesn’t turn off.

What are my options in utilizing the 5,1 tray or is there a way to modify the 5,1 to play nice with the 4,1 backplane I suppose?

The original CPU Tray in the machine was a single processor Quad Core with 4 RAM slots.


Thanks for any and all help in advance !!!!!

 

[StuAff]

Unfortunately, you need a 4,1 tray for a 4,1 backplane, even with the firmware flashed to 5,1. You've just found out why.

 

[tsialex]

Buy a mid-2010/mid-2012 backplane to match the CPU tray. Until you solve the SMC mismatch, 1.39f5 of the early-2009 backplane with the 1.39f11 of the mid-2010/mid-2012 CPU tray, all the fans will run full RPM 100% of the time.