Hi,
 I recently migrated to RME UCX (from Scarlett) and everything seems just fine except that the Virtual Guitarist Iron VST is clicking and poping to an unusable extent when I use it at 64 samples buffer size in ASIO. I have to increase the buffer size to atleast 512 samples for almost pop/click free operation and 1024 sounds like the best for this VST. Apparently I got used to the 64 samples setting and trying to see what I can do to get this specific VST working at atleast 128 if not lower.Ofcourse once this vst is played I can freeze it and continue at lower buffer size, but just wondering if  there is any setting that I can tweak in Sonar for this purpose.
Thanks in advance.

Have you checked for VG Iron updates? I've tested it with SONAR and a TASCAM interface, and didn't notice anything out of the ordinary.

Dont find any updates for VG Iron on their website. This is the only issue I have after upgrading to UCX !