I started having problem with the Cubase VST performance today.
I use cubase version 7.5.30 64bit runing on Windows 8.1 64bit using only 64bit plugins.
When I use softsynths that do not use disksamples there is no problems, including u-he Diva.
When I use omnisphere or kontakt then the vst performance suddenly rised from small 3-5% to a constant peak at 100% without me even toughing the keyboard.
I have already optimized my os for audiowork following the instructions at native instruments homepage. I tried optimizing the ASIO latency settings too. I tried to reduce cpu load of native instruments kontakt, but what is optimal 1 core? multiple core? or is that only in cubase these multiple core settings should be done. I uninstalled my new midi keyboard driver that I installed this morning, and I updated the firmware for my samsung evo drives and even ran a disk performance reparing software in order to make sure that my samsung evo drives were not the reason for this constant vst performance spike at 100%
Then I looked at the routing of my vst plugins. In this test I only had three vst instruments and two vst effect plugins. Both vst effect plugins were on the same track and were insert effects. I removed the second one ROOMVERB. So far it looked like that helped. Maybe Roomverb is causing the bug? or the preset I used is causing the bug, because I have not edited the roomverb preset. I used the preset Hall Grand Chamber. Perhaps Cubase cannot use multicore processors as good as I hoped, so perhaps it is a bad idea to have several vst effect plugins on the same track. This means that VST performance should have one bar for each cpu core, because the current one is not very useful at all.
I have not deactivated my antivirus software. Perhaps vst performance spike is cause by overload of the first cpu core.
I really dont want to switch to the latest pro tools with handles multiple cpu cores very good, because I like cubase and I even skipped studio one pro two month ago, so I want these ilogical vst performance spikes at a constant 100% to go away.