VST Performance/Playback Issue

hey guys, I hope this fits in here:

just got myself cubase 8 and I’m having big troubles with the VST performance, it’s at 100% nearly all the time which makes a fluent playback impossible.

I’ve tried stuff and read what I could find about it but I’m lost.

Soundcard:
It’s not the soundcard, the problem occurs on my focusrite, as well as the onboard soundcard as well as the focusrite via asio4all.
Latency is up ALL the way, ASIO guard is activated and on the highest level, audiopriority is boosted.
I tried various combinations of different Latencys and such, didn’t help.

Bios:
I tried disabling hyperthreading, speedstepping, fastboot and other power management programs in the BIOS, helped some other people, didn’t help me.

I tried installing the new update (8.0.20), made it a LOT worse, uninstalled it right away. Already tried reinstalling cubase 8 as a whole, didn’t help.

Already did all the optimizing stuff concerning power management in Windows and went through the whole device Manager as well.

The problem doesn’t occur in empty or “small” projects but it happens surprisingly fast as soon as I introduce a few vst instruments and effects, I haven’t had this issue in cubase 5 (running on the same machine) so I’m kinda confused.

Sometimes it runs smoothly for a few minutes, then it starts lagging or plays some very distorted sound which is unusable.

Windows 8.1
intel core i7
16gig ram

Getting really desperate here, basically impossible to work on anything right now :frowning:

I hope that’s all the relevant info…
Hope somebody has a hint that might get me in the right direction!
Thanks guys :slight_smile: