Typically, the culprit for something like that is either the audio interface or the network/wifi card. Unless you have a very old nVidia (pre-series 5, but as far as I remember, the 210 isn’t that old), I would exclude issues with the GPU.
You might want all AERO on to see if that solve the problem.
With your hdspe what Adat clock are you using ?
Ive found with my RME if im using the internal clock of the RME and not the source clock im always getting clicks and pops . … you never know
I"ve found in the past some Nvidia drivers can be a little flaky with Cubase. Disabling temporarily and running on windows default video driver will tell you if thats where you should be looking.
I had this when I updated my BIOS firmware, after disableing Hyperthreading and some eco settings regarding powerusage the pops went away.