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Need tips to track down very long render times
Hi Folks,
You local friendly noob again.
Just wanted to ask what you folks do to track down the source of very long render times. HDV to ProRes footage and sequence, 11 minutes in length.
But I’ve applied Primatte’s Keyer Pro and color correction. On my late 2008 MacBook pro 2.8 Ghz w/4GBs of RAM and a FW800 scratch drive I’m looking at 24 hours of render time.
Ok so I know with the complex filters applied and what not, long render times are just going to be what I get. But I’d expect my Mac to at least be working hard…
I note my CPU cores are only around 50% at most, I think it might be just not enough disk IO to feed the CPUs, but how can I really tell?
In Windows I would use perfmon and monitor my disk IO queues to see if the system was waiting for disk IO.
In OS X, Activity monitor shows my disk throughput, but it’s hardly anything, maybe 4MB/s at most.
50% of my memory is free.. etc etc..
So what do the pro’s do to track down these slow render times before they make the leap to buy the hardware to address it?
Thanks for your insight!
-Chris -
6 Replies
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The long render times are due to using HDV footage and the Primatte filter.
MBPro is not the fastest machine. Mac Pro would give you a lot more horsepower.
Steve Eisen
Eisen Video Productions
Board of Directors
Chicago Final Cut Pro Users Group -
[Chris Fisher] “50% of my memory is free”
FCP is a 32bit application. 32bit applications have a limit being able to only use 4GB of ram. FCP reserves 1.5GB of ram for drivers and frameworks and that only leaves 2.5GB of ram for FCP to use when rendering.
https://support.apple.com/kb/TA27734
So depending on how much memory you have, that 50% free memory may be completely normal.
There are no “technical solutions” to your “artistic problems”.
Don’t let technology get in the way of your creativity! -
To answer the core question, here’s how you find where your system is choking on the render time.
First….observe your timeline. If you’ve got parts that are 37 layers thick, and half of them have some sort of compositing mode set, and the other half have keyframes set for motion, scale, et al,….that’s gonna slow things down.
Second….highlight your timeline in 15, 30, 60 second chunks and render just those. If they go, that’s not the problem. If the are going at a good clip, then seem to stall out, cancel the render, and check where the render progress stopped at (those colorful thin lines at the top of your timeline….if it’s bluish, it’s rendered. The ones you’re looking for are going to be orange or red). Where the render stopped is where you’ve got a troublesome render spot. Nest it, and render so you don’t have to rerender if you accidently bump something by a frame or 3.
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Great tips Dennis, thanks so much I’ll try just that!
My timeline is fairly simple, 5 tracks, the background image, a track for a vector box that I overlay images inside on, an image track, the video track, then a lower third track on the top (typically motion templates).
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Steve –
Being a total rookie, can I ask what might be a really dumb question? Do I still get “penalized” in some ways for using HDV, even when I captured into final cut as ProRes using Apple’s HDV to ProRes method talked about here on the cow?
I ask this because – The other day I capture out of my HDMI port into my machine using a Matrox mx02 mini as ProRes and seemed to be able to get away with a lot more filters and effects before I really needed to render.
My understanding was if I bring HDV into FCP has ProRes what I am working with is true blue ProRes. Am I wrong? Is there still some kind of limitation aside from the limits of coming from lossy HDV with less color and quality… I guess, I am asking, is it not true ProRes or something?
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No, you’re fine on that front Chris, your post said your footage was HDV to ProRes which could easily be misinterpreted to meaning you had both HDV and ProRes footage in your timeline. As it is, as far as the codec goes, ProRes is ProRes regardless of original source …
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