I can see that the usbport.sys causes some CPU usage: -------------------------- DPC Info -------------------------- CPU Usage Summing By Module For the Whole Trace CPU Usage from 0 us to 49781250 us: CPU 0 Usage, CPU 1 Usage, usec %, usec %, Module 2423690 4.87, 2444616 4.91, USBPORT.SYS Have you installed the latest "Komplete Audio 6" drivers?