Got an interesting one here... Doing some testing on a 2007 Mac Pro 8-core 3.0GHz machine, and its CPU fans seem to regard their charges (the CPUs) with some degree of contempt. When under a sustained, heavy load, the CPU temps will climb and climb, eventually reaching 190F or so and causing the machine to shut off; all the while, the fans couldn't be bothered to budge from idle.
My testing is basically having Final Cut Pro X (v10.3.4) transcode some 4K Phantom 3 Pro footage to ProRes ("optimized" media). During transcode, Activity Monitor shows upwards of 700% CPU usage.
At first, I wondered if this was a product of running the machine beyond its pay grade on 10.11 El Capitan. I thought, perhaps SMC direction is absent for this machine in ElCap. So, I booted to the previous 10.7 Lion disk and retried (w/ FCP 10.0.9 this time). CPU usage appears to peak around 400%, so it takes longer, but temps still climb until the machine shuts off.
I've tried SMC reset w/ the power cord like Apple suggests, as well as resetting using the button on the logic board near the PCIe slots. A quick test using SMC Fan Control to bring the fans up to 2K RPM or so (600RPM is idle, I believe) easily kept the CPUs below 140F and no such shutdowns occurred. While this could work, I'm more interested in *why* it's behaving this way and how to fix it, rather than treating the symptoms.
Any suggestions?
Thx,
Fred
My testing is basically having Final Cut Pro X (v10.3.4) transcode some 4K Phantom 3 Pro footage to ProRes ("optimized" media). During transcode, Activity Monitor shows upwards of 700% CPU usage.
At first, I wondered if this was a product of running the machine beyond its pay grade on 10.11 El Capitan. I thought, perhaps SMC direction is absent for this machine in ElCap. So, I booted to the previous 10.7 Lion disk and retried (w/ FCP 10.0.9 this time). CPU usage appears to peak around 400%, so it takes longer, but temps still climb until the machine shuts off.
I've tried SMC reset w/ the power cord like Apple suggests, as well as resetting using the button on the logic board near the PCIe slots. A quick test using SMC Fan Control to bring the fans up to 2K RPM or so (600RPM is idle, I believe) easily kept the CPUs below 140F and no such shutdowns occurred. While this could work, I'm more interested in *why* it's behaving this way and how to fix it, rather than treating the symptoms.
Any suggestions?
Thx,
Fred