P2 decreases the memory clock during compute applications by 500 on 1080Ti’s (from 5500 to 5000). In my opinion it feels more stable to do memory overclocks with P2 disabled for some reason that I’m not able explain. Now, Zcash doesn’t benefit very much from memory overclocks with lower power limits (80% and lower) so it’s kinda pointless to do it if you’re going for power efficiency rigs.
With this app you can disable P2 https://ci.appveyor.com/project/Orbmu2k/nvidiaprofileinspector/build/artifacts
Please I’m not encouraging anyone to do it because it might have some risks if you exaggerate on the memory overclock.