Best setting for native HD dubber/video playback

[Brandonx1]

Hi All,
I recently started using a HD Native rig for stem recording and video playback. Does anyone know the best settings for HD quicktime playback and stem recording? I just had a session with an HD quicktime in it and the dubber rig choked with 2 processors/ 85% and 64 sample buffer. I raised the processer to 4 /95% (still 64 sample buffer), which fixed that problem and made the rig run much smoother. I didn't know those settings in the playback engine effected quicktime playback as well. Any thoughts?

This is on a quad 2.6 mac pro running 10.6.2 and PT HD Native 9.0.3
Best

[Brent_Sydney]

Your QT movie is driven by the operating system, outside of the PT environment in a way - so if you assign all CPU power to PT you starve the OS of grunt and get poor QT performance. If its a satellite rig for dubbing, you shouldnt need to run many plugins right? So axe your CPU usage. If youve got 16 cores available, only assign 8 to PT, leaving the rest to QT.
I think I remember reading something about the decklink cards liking a PB buffer size of 1024 as well.
The PTHDNative card compensates for IO latency (tickbox in the hardware settings I think) so you can play with these settings without fear of audio sync issues AFAIK.
I can test this more next week - just got a native dubber on my vid satellite on demo a few days ago.

[Brandonx1]

Hi Brent,
This is what I thought as well, but I seem to be having better Performance with hd quicktimes with all cores selected in the PT playback engin and 95% usage. Odd to me to. Also I took a look at the activity monitor and the only process taking up any CPU PT. The QuickTime process is 0%. another odd one.

Lastly, if you turn on LLM with an hd native card, you only get one monitor mix, I think. I need all the outputs to be really low latency which is why I'm using 64 smaller buffer. Is this all correct?
Thanks