I realize this might be a question for RME, but using their products/drivers on Windows, is it possible to record in Cubase while simultaneously using the same interface/channels for Waves Live?
Hi,
It depends, if this is a Multiclient ASIO. Do you really need ASIO in both applications? Maybe different kind of sound driver would work for one of the application. Maybe you don’t need real-time for both of them.
yes, RME Interfaces (I use the UCX) can do multi client ASIO - sometimes I´m running Waves GTR and Cubase - no problem - system is win 8.1 pro
Then the answer is: yes. 
That’s what I thought, however the last time I tried this, Cubase stopped recording every couple minutes saying something ridiculous like “too many tracks” or something. Setting buffer didn’t help. I was recording 24-bit/48kHz, only 10-12 tracks, and to a SSD in a very fast Core i7 laptop. There’s no reason that should stop even on the lowest buffer settings.
Hi,
How was the level of the Disk load in the Performance window?
Didn’t even budge.
Did you see any CPU load or something on the system level?
Nope. I’m trying again now and it’s still doing this with only Cubase 8.5 running, zero background apps. Latest RME drivers, Windows 10, Core i7, 16GB RAM, tracking to SSD. Buffer is set to 1024 currently.
Is RME driver fully compatible with Windows 10?
Could you try different ASIO Guard levels, please?
Is driver set to “allow exclusive” mode or release driver in background?
Check your Windows system audio Recording Device advanced settings for this.
There’s usually another setting in Cubase - Devices - Device Setup