When you do a System Image, you need to indicate which drives you want in the image. If you don't, it will default to the Windows drive only (C:\). The only drive you can't include in the System image backup is the drive where the System Image is going to be stored in.
I use Acronis to backup my other drives or USB drives and use System Image only for my Windows Drive.
Whenever I've been playing, I noticed that the GPU would hover around 50 C,
which is a lot cooler than the 74 C it used to run at before everything
went pretty slow.