- Feb 12, 2015
Remember it's not just the work that the CPUs might be doing with what's attached to the PCIe controller, but also the PCIe controller itself. When this is resident on the CPU, simply shunting data back and forth over the PCIe bus - even if you're not doing anything computationally expensive with it - will still generate a fair amount of heat. Moving lots of bits is expensive.That all depends on how the OS schedules the work; it may be that I/O-intensive processes (which spend much of their time waiting) get scheduled on the CPU with the I/O, while CPU-intensive processes get scheduled on the other CPU.
Of course it'd be interesting to see if the temperature difference holds true for a system sitting completely idle, i.e. little to no IO at all.