ForumsSoftware ← Windows/Virta/Ableton Live 9.6 Weird CPU Spike with no MIDI input.

System: Windows 10 Pro Asus MB, Core i5-3450 3.1ghz, 16mb ram, Focusrite Saffire Pro 40, UAD-2 PCIe card.

Put the whole Ableton project I was working on here:

http://www.cornwarning.com/xfer/VirtaCPUSpike.zip

Factory drum rack on Track one, processed by Virta
MIDI clips routed to Virta on track 2
Kaivo track 3 making tinkly noises
bass track 4 (minimoog v vst + max4live bass instrument in an instrument rack)
Ableton Live factory drum rack on track 5.

Runs about 40% CPU and plays fine 768 samples ASIO buffer UNTIL ...

I stop all MIDI clips on track 2. This means Virta has no midi input, though it's still getting audio from the drum rack. The CPU spikes up to 150% and the sound gets all distorted and the Live clock slows down.

Thanks for sharing this project and info. Can you tell me if the other tracks (besides the Virta-related ones) are necessary to cause the problem?

I'll investigate.

Two things.

I deleted the bass and Kaivo tracks and I could still get it to spike by turning off MIDI... didn't instantly have an issue but could get it to glitch by adding a MIDI clip and adding notes and then stopping clips.

Given my system which is 4 years old at this point I can run 4 voices of Virta and 4 of Kaivo mostly with Live reporting a 50% CPU load.

One thing I noticed, if I close and re-open Live, then load that live set, Virta seems to only use one voice of polyphony. I need to change to another patch and change back to get the specified polyphony back...