More succinctly, to close out the thought-
Since that system performance, and reaching this (max) “capacity” is associated with flawless (no drop-out) audio, and I believe ASIO performance basically depends on how well and promptly the audio software can keep up filling the ASIO buffer to avoid flow interruptions and thus drop-outs, I believe there is a strong relationship between ASIO performance and system performance. So excluding the ASIO hardware/driver latency factor, it is Cubase + your system’s processing power that determine what that “capacity” is to be.
On the one side of my tests, I did see a slightly lower capacity when I switched my CPU to stock speeds, e.g. no OC’ing, more noticeable on the VEP series of tests. Which I think substantiate my above observation. But at the same time, the system speed difference was not substantially different for me to see major changes.
It also intrigues me that some people have reported such effect (no major improvement, that is) when they upgrade their systems. And I can only try an educated guess at it in saying that it might well be the case if Cubase’s overall “VST Performance” is being somewhat limited by the way their code now handles all the processing, or multi-processing. Why in turn might be in line with the observation that C7.5 is not fully utilizing the multi-core capacity, at least in my tests results.
Would welcome thoughts and comments. (and sorry for the wordiness)