I've recently upgraded one of my company's Blackmagic Multibridge Pro NLEs to CS5:
AE CS5 does not play realtime RAM preview of HD1080 video when displayed through the Blackmagic video output (even as low as 1/8 resolution).
1.) Lowering resolution (even down to 1/8) does not help.
2.) Matching scale % to resolution % does not help.
3.) Doing #s 1-3 in combination gets very close to realtime, but CS4 did not require all of this.
4.) If I switch AE output to "computer monitor only" I get realtime.
5.) SD comps played through Blackmagic output achieve realtime.
In CS4, HD Blackmagic output WAS realtime. I have made all memory/multiprocessing settings match the CS4 configuration, but this has not helped.
Also, both AE and the Blackmagic driver are the most current version. I have no desire to revert to CS4... Anyone have any ideas?
To answer my own question:
I lowered the project's color settings to 8 bits per channel--and now all HD RAM previewing (even at full resolution) seems to be playing back realtime!
Hope this thread can be helpful to anyone else experiencing the same issue.