this is really strange, but on my pc there is no difference in cpu load for both versions. no idea why it is so? might be the reason I'm using 1080ti not the new version of nvidia cards with this modern tensor cores?
also I have to mention that performance change is very low, so basically no need to upgrade imo, better save time and stay with current version.
I updated the driver after the security alert made by nvidia ... In my case it affected the cpu overload, maybe for other gpus models this doesn't really happen.
https://www.techradar.com/news/nvidia-graphics-cards-vulnerable-to-security-flaw