With Driver 21.4.1 I was able to lock my core clock to a certain number. I was surprised with what I saw, stock settings it stays at around 900mhz with 90% usage, which looks logical looking at the relatively low clock that is uses. Then I used a core clock at around 2200mhz and locked that via driver which made the usage being stuck at around 35%. This is a very weird behavior and I can't tell if this is a game or driver issue. I will test driver 21.5.1 tomorrow and see if that brings any new oddities to the table. I'd really like to help in any way possible bungie...