My current RME HDSP9632 above. I remember the first interfaces I tried on W7 was for firewire, and they had different in/out specs in Reaper and in Sonar. I tried these interfaces on my old XP daw since I put firewire cards there too - and it was different for in/out as well. I always thought it had to do with interface actually having slower A/D than D/A or something. I tried Focusrite and TC Electronics firewire stuff then. You mean it's OS thingy? I remember Sonar had real difficulty playing VSTi clean, if I didn't set latency up at least to what highest was for 128 samples(162 or something). I tried 128 samples with audio and it was fine, but VSTi crackled. So I raised to 192 samples and VSTi was fine. So I felt Sonar had some crappy handling of VSTi that didn't handle this right. My old RME Hammerfall in XP has same in and out, but firewire stuff did not, they were different. So I gathered - different interfaces.