VST Performance and buffer size.

Hello everyone, Cubase Pro 9 performs very bad when in lower buffer sizes on my system. For example, 128 or 256 samples. It goes to red often and makes audio dropouts. CPU usage is at best 30% in task manager but simple projects have audio dropouts along with red lights in VST performance meter. Specially when I add mastering plugins on the master bus. Now, I tried third party plugins like iZotope Ozone, Limiter 6 etc. I also checked with only Steinberg plugins like Steinberg Multiband compressor and limiter to see if the situation improves but same results!

But on the very same system, Sonar runs very smoothly even with more plugins (in Master bus too) and much heavier projects!

Any help or ideas?

Do you use any VST instruments?

Yes! Thank you! I just figured out after reading so many things that I had to turn off the ‘‘Simultaneous Multi-Threading’’ from bios. And it worked! Thank you though fro replying! God bless you.