Unreasonable CPU usage (Mac Sierra, Nuendo 8.1)

I’m relatively new to using Nuendo and I’ve been having this issue where audio playback will start to cut out and become choppy or go completely silent altogether, with Activity Monitor showing upwards of 200% cpu usage from the program. The weird thing is that the issue happens even with all plugins killed or only a single audio track playing. If I let the program sit for a little while, it works fine for about forty seconds before the issue arises again. This is super frustrating and it’s really kicking my workflow in the jewels.

I’ve tried checking the VST Performance window, and it’s showing that the average load is breaching the limit, but the real-time peak is staying extremely low. This only has me more confused.

Any idea what’s going on here?

I am having the same issue here. I worked on a project last week and everything was fine, but when I loaded it back today my average load is very unstable. Sometime it is at 25% and for no apparent reason it rises to 80 90% and peaking. I disable every plug in, but nothing seems to work. The green bar is moving non stop between 25 - 90% even when nothing is playing. I didn’t have any issue before. My computer runs 32g of Ram and has a I7 2.8Ghz.

What might contribute to the high CPU usage is a high base usage. I don’t know your system, but on my laptop, in a very small project with just one or two tracks Nuendo is already at 75-100 % CPU while there’s nearly nothing going on in the VST performance. See attached image. I tried disabling multi processing, changing the ASIO Guard settings, etc… no change.
That might explain why your system gets under heavy load when there’s actually something going on in the VST performance :slight_smile:
Any chance that your processor uses Hyperthreading?

macOS with High Sierra, Nuendo 8.1, 2.3 GHz i5 with 8 GB RAM.