I am not fond of putting sample libraries on the same drive as sessions. With only 2 drives, I would put those on the system drive, OR, try putting the session on drive C: (this was not good in the days of spinning drives, but a fast SSD should be fine with it).
Set drive cache to 4-6GB("normal" is actually none)
Freeze or Commit the VI tracks as soon as each is recorded to see if that helps(if it does, then that indicates my first comment may have merit)
