MP 7,1 Mac Pro keeps shutting down after 6900 XT install + redshift render (HELP)

[Korie Cull]

Hello all!

I'm having a serious issue.

I recently brought a 6900 XT to render in Redshift. Everything works fine in the OS, GPU is supported and I can browse and file etc...

However as soon as I render in Cinema 4D/Redshift my screen goes green/black and my system shuts down and restarts.

(I have also re-intsalled MacOS/tried different versions of the software/and removed hardware one by one.)

I noticed that when I render using the 6900 XT the power goes all the way up to 200-300w and then the system turns off.

So I think maybe this could be a power spike issue however surly not because the PSU on the Mac Pro can handle more than 1 or 2 gpu’s at a time? Plus I tried only the Radeon 6900 XT in the Mac Pro by itself and it still happened.

Video footage below of the issue:

Specs of the system are below:
Mac Pro 7,1
macOS 13 - 13.2.1
3.2 GHz 16-Core Intel Xeon W
128 GB 2933 MHz DDR4
AMD Radeon RX 6900 XT 16 GB via two Belkin 8-pin to 6+2 pin power cables.

Any help would be very very appreciated as I need to render!!!

Thanks,

 

[cobra521]

Korie,

Interesting symptom. I had a similar thing, but at least on the surface it would seem to have nothing to do with your problem, sorry.

I used AFP to connect to Synology NASes for a year or more. Somewhere along the various updates to Apple's OS (I think it may have started with Ventura) my computer would reboot immediately when I clicked on one of the NAS unit's icons. No hesitation, no pause, just immediate and total reboot. And no meaningful error message upon restart.

The only thing I could find to make it stop doing that was to switch all my local network storage access settings to SMB. End of problem at least for me. I tried to get help from Apple and from Synology - no reply. Don't ask how I figured out how to make it stop - probably monkeys and typewriters. It has been OK since...

Only point I can think of is that MacOS Ventura combined with the 7,1 Mac Pro is "tender." By that I mean some little off-the-wall problem can kill it, completely and quickly. In some respects this combo seems balanced teeteringly; the least little thing can shut it off, or at least cause a hard reboot.

I guess if you could downgrade the MacOS one level which may or may not be practical, or go to a different video card, you might stand a chance of getting your project done. Otherwise if you have the luxury of time, maybe the future major upgrade from Ventura to whatever's next may work for you.

Sorry for not helping,

Tom