Regarding DPC readout:
Code:
Windows 8 Compatibility: The DPC latency utility runs on Windows 8 but does not show correct values.
from:
http://www.thesycon.de/deu/latency_check.shtml
Accidentaly, I also own RME babyface and everything runs fine on Win8 even at 48 spl latency (didn't do any real tests, but it's pretty much feels the same as Win7, in regards to performance)
Do you have the latest drivers and firmware for babyface?