I run Digital Performer 9.01 under OS10.10.5 on a 2012 iMac maxed out with RAM and a UAD Apollo interface. I'm using the latest VEP plug-in, MAS version, within DP. On a track I'm currently recording, I have 3 VI plug-ins in the VEP server, routing their outputs to separate outputs of VEP and back into DP for recording on to separate tracks. I'm using VEP outputs 3-16, 8 stereo pairs (even though some of the tracks are mono, since VEP doesn't have mono outs). the output 1&2 pair is reserved for the VEP Master Bus, which I use occasionally.
I play MIDI live into to VEP, the audio on any VI routed to any of the above outputs is noticeably late coming back into DP. If I re-route the output the VI to the Master Bus, the latency disappears. This happens no matter which VI I am playing.
DP pre-gen settings have no effect on this, nor does host buffer multiplier. I could always route the instrument I'm recording to outputs 1&2, but why should the other outputs exhibit this latency when the outhers don't? I feel maybe I am missing something...
Thanks,
Tony