Dell precision T5600- Sierra 10.12.6

[Logitech 96]

Goodmorning, 

 
after a night of tests, I've finally completed this Sierra installation on my Precision T5600. After fixing the Kernel load cache (0x9 error), I'm now trying to get the rest of the system working

HW specifications:

CPU Xeon E5 2667 2.9ghz
Ram 16gb ECC
Gpu Nvidia Quadro 4000
Chipset c600 series
Audio ALC269


What works:
-GPU with patched Nvidia web drivers
-System see all 8 ram slots 
-System see all 6 cores
-Sata Chipset recognized as C600/x79 series
-USB 2.0
-Wifi

What doesn't work:
-CPU name on System informations (CPU-> 2.89ghz "unknow")
-Audio (front or back connector)
-SAS drive chip
-USB 3.0

The system is stable (SMBios MacPro 5,1 and iMac 14,3 boot fine but MacPro 6,1 get a black screen) but many time it slow down (spinning wheel) 

Any suggestions to get all work?
I haven't a patched DSDT or SSDT


(Excuse me for my bad english)