https://help.nanominer.org/article/168-gpu-and-cpu-control

By default Nanominer sets the memTweak option to 1. This slightly improves memory timings. However it introduces a little bit of UI lag. This can be a problem if you are trying to use your computer for other tasks. The simple resolution is to change/add the memTweak setting to 0.

memTweak=0

Example config

wallet = WALLET_ADDRESS
; Coin to mine.
coin = ETH
; (Optional) Rig (worker) name.
rigName = EthMiner
memTweak=0