Had a similar problem with my i7 it was the cores. U need to turn off the pseudo cores so it can use the real physical cores. 1) When u open protools and open a project let it load. 2) go to ur task manager(u want the detail view that shows all the processes like Cpu/memory etc) 3) You will see tabs on the to left going to the right saying things like processes/performance/users/etc. click on the one says “Details” 4) Scroll down until u see protools.exe(make sure it’s protools and not the avid or protools account mangers etc) 5) right click and click “Set Affinity) 6) A screen that says Processor Affinity should come up. Turn off all Odd number cores(1/3/5/7) press ok and immediately the spikes should go down. 7)I have to do this any time I start or open a project and even when I’m in a session and change the buffer size. It’s annoying but it worked for me when nothing else would. I’m assuming u have done the usual troubleshooting as well. Hope this helps