Scrub Issue - Native vs. TDM Plugins

[Kevin Peters]

Scenario:
I have a Pro Tools 10 HD session up with two tracks and the same audio file on each track. I put the same plugin on each track, but one is the native (or RTAS) version and the other is the DSP (or TDM) version.

Say the plugin is a simple EQ, and I put the same curves on both plugins. Then when I scrub the region on the track with the native version of the EQ, I hear the region as is, as if it bypasses the plugin information. But when I scrub on the other track with the TDM plugin, I hear the region as if it passes through the plugin with all the EQ curves that I set (as expected).

Questions:
Am I missing something very simple here? Is this normal behavior for native plugins? And its not just EQs, I've tried it with a handful of other plugins.

The interesting thing is when I try it at home with Pro Tools 10 (non-HD, so all the plugins are RTAS), when I scrub it passes through all the plugins on the track.

I don't have the exact tech specs off hand right now, but I've tried it on two Mac Pros with Pro Tools 10 HD. My home computer is a Macbook Pro. I can get the exact tech specs if anyone thinks that would help.

[Kevin Peters]

I've just tested the same scenario in Pro Tools 8 on the same systems and it does the same exact thing.

Edit* I've also tested this issue on Pro Tool 6 with the same results. So obviously this has been around for a long time, I'm just surprised I can't find anyone else complaining about this before now. I guess in the past if you had a system with DSP, you always just use the TDM plugins so thats why no one would have noticed.

Can anyone try this out and confirm?

[DigiTechSupt]

After a bit of digging with Engineering it looks like this is indeed a limitation of RTAS plug-ins running on TDM (HD/Accel) hardware.

Best thing we could recommend at this point would be to post it to http://protools.ideascale.com

Sorry that we don't have better news here.