As this one spreads about several threads I make a temporary new one:

MC wrote:
- Windows WDM playback via USB suffers from random clicks and pops when using buffer sizes higher than 256 samples. To get rid of these do not use 512 and up, or exit TM FX completely. This problem is also present in release driver 0.966. We are working on a fix.

If you suffer from clicks under WDM with Babyface, Fireface UC or Fireface UFX, although you don't have any CPU or DPC problems, please try version 0.979:

https://archiv.rme-audio.de/download/usb_win_0979.zip

Also please note that this is the latest driver with lots of changes as explained here:

http://www.rme-audio.de/forum/viewtopic … 215#p52215