Okay - so I’m using a 4-core (8 multithread) i7 CPU with Windows 10 and 32GB Ram - and SSD drives for my VST instruments. Previously, using Windows 7 and Cubase 8, I could load and use tons of VST instruments, like the EW Diamond Orchestra with multiple microphones loaded.
Since upgrading to Windows 10 and Cubase 11 I have serious performance issues. Loading only a few instruments or plugins results in processor overloads and spikes. Often times you see the processor overloading when the system is idle. Hence ASIO guard is suspected. However, delving into those settings - disabling it, turning on - off all possible settings - including multi-processing. Everything other than the default makes the situation even worse - which leads me to suspect that there is some deeper issue with Cubase 11 and Windows 10 - at least my machine - whereby Cubase is not able to access the multiprocessing capabilities of my CPU. When checking the Resource Monitor , however, I see activity on all physical CPUs.
Accordingly I have just performed a control test: loading my VST instruments into Vienna Ensemble Server - and playing the same track that way. Lo and behold, gone are any issues with crackles and pops with the instruments. Now the processor load (and ASIO guard) in Cubase is unaffected by playback - and obviously VEP is not troubled by my machine and is able to playback polyphonically the same load without stressing my processor.