CPU mining add +10% hashrate to GPU mining

Simply.. I have 1080ti and I'm mining at 680/690 sol with normal settings (80tdp +200core +500mem...) and then I tried to mine monero with cpu too (ryzen 1700), What happen? My 1080ti speedup to 720/730 while cpu mining. If I stop cpu miner come back to 680/690.

I really cannot understand why..

Interesting. That’s a good problem I suppose!

What program are you using to mine 2 different algorithms with cpu/gpu?