High CPU load when VST selected

Just as a public service announcement in case anyone else hits this issue…

In an empty project I would create 1 audio track and 1 Instrument track, loading the Ivory 2.5 VST 64 bit plugin. Without any MIDI input ( not playing anything or playing anything back ), the Audio Performance tab would show a pretty much constant usage of 70-100% of the CPU ( not reflected in Task Manager - Performance ). If I selected the empty Audio track, the CPU usage would go back down to 10-20% usage. This resulted in a bunch of dropouts etc. making it unusable even with a 2048 buffer size. This is in the Cubase 10 forum but I was also seeing this in 9.5. I was also seeing performance spikes in other VST’s, but Ivory II was by far the worst for some reason.

I got in touch with the Steinberg Support who were extremely quick to respond and helpful, and they recommended a bunch of solutions. In the end, what fixed the issue was switching the PC from a “Balanced” power scheme to a “High Performance” power scheme. Toggling between those 2 power schemes with Cubase open, the Ivory II track selected, and the Audio Performance tab open would show it switching between 70-100% usage and 10-20% usage.

Spent hours trying a bunch of other fixes unsuccessfully, so hopefully this’ll help someone. Again shout out to the support guys who were really on the ball.

PC specs:

  • Windows 64 bit pro
  • Intel i9900k
  • RME Fireface UFX
  • NVidia 2080 ti Strix
  • G.SKILL TridentZ Series 32GB (4 x 8GB) DDR4 3200 Model F4-3200C16Q-32GTZSW
  • Samsung SSD 970 EVO ( Windows drive )
  • Intel 600p ( drives with samples / project data )

What didn’t work:

  • I had the issues on 9.5, read a couple misc support docs outlining possible issues with processors with > 14 threads, and added the audioengine.properties file conatining the audioengine.threads.max=14 to the appropriate C:/Users/AppData/… location.
  • Disabled the XMP RAM profile on the motherboard
  • Updated/Reinstalled the RME Fireface UFX driver
  • Updated/Reinstalled the RME USB driver
  • Updated/Reinstalled the RME firmware
  • Changed the USB cord and port used by the RME
  • Updated to Cubase 10 from 9.5 based on the hope the improved thread usage would fix the issue
  • Reinstalled the Ivory VST
  • Tried all combinations of removing the ASIO Guard, and it’s various settings
  • Disabled Multi-core processing
  • Enabled/Disabled the Steinberg power optimization
  • Disabled all other audio devices and drivers other than the RME Fireface UFX
  • Updated NVidia drivers
  • Installed limited set of NVidia drivers ( without all the geforce experience crap )
  • Windows update to the patch released that day
  • Disable all background programs
  • Toggling USB Selective Suspend

Fixes I didn’t get to that were recommended by Support ( I reached the Power Scheme fix prior to trying these ):

  • Disable C-States, EIST, SpeedStep and any throttling options
  • Test with Hyper Threading on and off (these days under normal conditions HT is no longer source of issue, but quite an aid)