[Darryl Ramm]

OK so that's a NUC like system with laptop CPU and memory. I have no idea how good this will be for Pro Tools, lots will come down to cooling. Sandra is not reporting memory properly, that may be a Sandra bug, or maybe not a good sign the PC is OK. Are the DIMMs on motherboard approved compatibility list? Also some underspec (for Pro Tools audio) drives.

But still it is most likely to be faulty plugins, denormalization, or corrupt sessions. You had a system with problems and you upgraded it to more powerful hardware... that hardware behaving differently/consuming more resources does not mean it's the hardware necessarily at fault.

You need to work through careful troubleshooting to work out what is going on. If you remove *all* AAX and RTAS plugin files what happens? I can't remember if PT 10 does the automatic restore magic for plugins like later version do. But just move all plugins out of the both plugin folders and if needed (if they don't get automatically reinstalled when Pro Tools starts) manually reinstall the base Pro Tools 10 plugins, and nothing else. Test starting with new empty session... what happens? Make big bold change early on to find something that works as expected. If you can't get a vanilla setup working with the PC then it may be a hardware issue and you should think about getting rid of the PC. But I doubt that is an issue

You have got a range of drives there, including a crappy WD green external drive and a slow Seagate drive to an NVMe SSD used as a boot drive. it's not clear what drive you are running sessions from, but just to exclude that I would be putting any test sessions on the fast NVMe boot drive (just stick them on the boot partition, that's going to be much faster than anything else you have).

Don't keep playing with #CPU settings, just set that to the number of physical cores -1. That might not be optimal but it may help with any hyper threading issues with some plugins, and you might try disabling hyperthreading all together to tune things future, but for now you need to find the causes of gross problems you are seeing.