thats temps sounds better… please report back whether at least the pc shutdowns/reboots are then no longer happens 
And also an additional note about “same fps, old vs new pc”. You can also check some benchmark tools whether your pc is within the expected range ( 3dmark, whatsever ). If the results are comparable with other systems with same hardware, we can only search some msfs settings which may cause that. Otherwise the issue is somewhere else…