50% on all cores... yea, I know...
But the odd thing was like I said, I didn't see any improvements with that option on....
Hmmm... I don't want to unfairly tarnish the software author, but excessive CPU use in a GPU miner sort of sounds like some backdoor Cryptonight hashing is going on, eh?
Not sure which release that you are referring to -- polling was turned on by default in previous version but is turned off by default in 3.0.0.
Enabling polling does lead to high CPU usages although it may or may not give you some extra hashrate. There is a detailed explanation on the current trade offs between CPU usages and GPU utilization at
https://www.bminer.me/faqI encourage you to try the latest version and report the results back.