P50 DPC latency problems

[athlon64]

Hello.

So i replaced my HP zbook g1 with a lenovo P50.
The configuration is: 6820HQ, 32GB RAM, Quadro M2000M, Samsung 512GB NVME.

The main usage is audio production (Avid protools). So having low DPC latencies is important to me.

The last lenovo i had (T540P) Had huge problems here with the intel NIC. But it turned out to be a hardware problem.

My new P50 when i first started latencymon, had a lot of spikes to about a max of 4ms (highest execution time).

So i track these problems down, they are caused by my nvidia quadro M2000M. The biggest DPC jumps are caused by nvidia drivers.

I tracked the problem further. The jumps happen when my card changes clock speeds. I somehow managed to lock it at maximum speeds and the DPC jumps stopped happening.

But now from some reason, even if in the nvidia control pannel setting i use "prefer constant performance" option, it still downclocks. I can't figure out why.

So i have multiple questions. 1. How can i lock my GPU clock speeds?

Why is this happening, my zbook had no DPC problems out of the box.
I tried multiple versions of nvidia drivers. Didn't make a difference.

Also sometimes the storageport driver and the network interface controller have latency spikes, but it really doesn't happen very often. The nvidia drivers are the biggest problem.