Hi, eXtremal! I have the following problem. I can not launch your miner on nvidia 1080 good. I have 8 cards. On 4 cards the miner works well, but as I launch 5+ card I have an issue - the processor is loaded 100% and the hashrate starts to drop. There are no such problems on AMD cards. Maybe some settings?
What CPU are you using? Try increasing or decreasing the CPU offload.
Even with a GPU miner this coin is CPU heavy, more cards = higher CPU usage. Also Nvidia pushes more to the CPU then AMD