Awesome Editing, Mediocre Transcoding
To me Avid MC's transcoding is a bit too mysterious. When you are transcoding a batch of clips in the foreground it doesn't tell you what clip it is working on. Which would be helpful when you are doing large batches and it hits a clip that is corrupt. Background encoding does tell you what clips it has done, which clips are left and what clip it is working on. However, it doesn't bother to give you any elapsed or remain time estimates.. Both are fatally flawed...and lazy if you ask me. But at least I have "The Lords Prayer".
I am currently doing a large transcode in Avid MC 8.5. I have about 15tb of R3D 5k files that I am transcoding to 4k DNxHR LB at 1/2 debayer. The sytem I am working on is pretty good 5,1 12 core, but modest in some ways. I don't have a Red Rocket-X or even a Titan X. Just a modest HD 7950 graphics card. The source is coming form an array of Lacie Rugged USB 3.0 drives and I am transcoding it to my humble G-Speed Q RAID 5 via eSata. Needless to say this is a looooonnnnnggggg arduous task. But in attempting to do this the most efficient way I have learned a few things...
Foreground vs. Background Transcoding
Foreground is what it is. Doesn't give you jack $#!% for info. The speed is fair-ish, but it doesn't seem to take full advantage of system resources. You can only do one bin at a time (unless you do some media manager tricks) and you are locked out of the system with no ability to pause the process once you start.
Background encoding is great. You can set multiple bins to transcode and forget it. However, even if you leave the machine uninterferred with, in my experience it seems that background transcoding takes about 60% longer than foreground encoding. An anomally I can't explain to myself but...lord give me the patience to accept the things I cannot change. Bottom line is Background takes about 60% longer.
An example of this (and the reason I have time to even write this post) is that I am in the middle of a big transcode process. 15tb or R3D files to 4K DNxHR. On my system config its taking about 5 to 1 to transcode foreground and 8 to 1 transcode background. I haven't bothered to figure how much time its going to take to do the whole transcode process. About 120 hours I would guess.
What about both? (evil laugh)
Desparate to expedite this process I wondered... What would happen if I transcode in the background and the foreground at the same time. Holy $#!% am I glad I decided to try that!!! On my my 12 core system transcoding in the background does not slow down foreground transcodes. Obviously the foreground is NOT taking full advantage of the system the way say Media Encoder would. The background transcode times do drop from 8:1 transcode times to about 12:1. But who cares? Everything it is dong in the background is a bonus since it doesn't slow down the foreground! This might knock my 120 hour project down to under 100 hours!
Bottlenecks
I have not tested this observation thoroughly. My source footage is coming from an array of drives. So I can set up my background and forground transcodes to be sourcing separate drives on separate channels. Not sure if this would work as well if they were all coming from the same drive...you might hit a bottle neck. But give it a whirl and let me know what you observe.
How to find out how long it took to transcode a clip?
If you want to know how long it took to transcode individual clips just go into the media drive and sort by date modified. The clips will get sorted in order of creation with a gap of time in between. Compare the length of time between two clips to the duration of the clip. The do some math to create a ratio. 5:1 would mean it took 5 mins to transcode this 1 minute clip or 10 mins to create a 2 min clip, etc.
If you happen to have an extra RedRocket-X card just laying around please send it my way. Otherwise, please give this a test on your system and post what you observe. And remember...
EVERYTIME A FILE IS TRANSCODED AN ANGEL GETS IT WINGS.