MP 1,1-5,1 Intermittent Boot problem

[dono42]

I have a 5,1 (original owner) that has been running fine for a long period of time. Most recent change was the addition of RocketU 1344D about 3 months ago. Recently it would boot intermittently, started maybe every other boot, reset with the power button, over time it became worse and then did not boot. Started by replacing the graphics card with the original ATI 5770, same result. Noticed outmp cpu a/b both flashed when the power cord was connected and removed. Diag button pressed show 5v stby amber. Power on, all fans running, diag button pressed showed 5v stby amber, psu pwrok green, sys pg green, no efi done. I removed everything but the gpu and a hhd with high sierra, boots. Ran AHD it passes. Added the pci cards one at a time, boots after each addition. Replaced the gpu with the RX580, boots. Cycled through 20 shutdown and reboots, all worked. Just what I need an intermittent boot problem. I plan on booting it a few time a day to see if it finally breaks something. Any words of wisdom?

 

[dono42]

About a month ago my 5,1 finally died, bad power supply. Question, can I safely run the SP Radeon RX580 8GB without the Pixlas mod? I did the mod over year ago on the original power supply. I don't think the mod attributed to the failure of the power supply after all it was ~12 years old. I can certainly do the mod again but if I don't have to I wont. Now OCLP Big Sur.

 

[tsialex]

About a month ago my 5,1 finally died, bad power supply. Question, can I safely run the SP Radeon RX580 8GB without the Pixlas mod? I did the mod over year ago on the original power supply. I don't think the mod attributed to the failure of the power supply after all it was ~12 years old. I can certainly do the mod again but if I don't have to I wont. Now OCLP Big Sur.

Even the Apple recommended Sapphire Pulse can emergency SMC shutdown a Mac Pro when being used full throttle.

If your workflow is light, you won't see a shutdown, but if you have a GPU bound workflow or like to play games, you will see SMC emergency shutdowns. Even more so if your PSU is not up to spec.

You can use a eVGA PowerLink and equalize the load between the two PCIe AUX connectors, eliminating most if not all shutdowns when using a non-overclocked RX 580 without the need of a Pixla's mod.

 

[Davehillbo]

I dont think an RX580 should trip the power supply, I use an overclocked 980ti and that works perfectly well.