VST spikes causing audio drop and freeze during mixdown

  1. Create empty project
  2. Add an audio track
  3. Add a VST plug-in from PowerCore Compact (http://www.tcelectronic.com/powercore-compact/) connected to PC via Digitus DS-30201-3 PCI-E fire wire card
  4. Work on a project.
    -> After approximately 3 minutes audio playback stops while VST performance monitor shows permanent spike. Only solution is to restart Cubase for another 3 minutes of work. Also when i’m trying to export mixdown (with VST plug-in on) to mp3 Cubase freezes at random percentage and only way is to kill it with Windows task manager.

My sound card is HDSP 9652 http://www.rme-audio.de/en/products/hdsp_9652.php

Kind regards,

PC specs:

Intel Core i7-6700 /3.4GHz, 8MB

Gigabyte GA-Z170-D3H /Z170, DDR4, LGA1151

DDR4 8GB (2x4GB) 3000MHz CL15 Corsair Vengeance

SSD 2.5" Goodram CX100 240GB (560MB/500MB/s)

Gigabyte GeForce GTX 950 OC 2GB DDR5 128bit

DS-30201-3 PIC-E firewire

Windows 7 Professional OEM 64Bit PL SP1

I’ve cheked with latency chekcer. Portcls.sys seems to be causing the problem with latency. See attachment. Any advice anyone?