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How to speed up render timesPosted by DM
Need advice on the most effective way to speed up renders
What is the main cause of slow renders? Working with 1080 XDCAM and HDV formats. However, the projects are up to 2 hours in length. Final render times are killing us. Medium amount of effects. 1-nor enough RAM. 2-Drive access speeds? 3-Other? 4-All of the above My system is non-raid, internal drive and FireWire 800 based Mac Pro dual quad core 6 gigs of RAM 4 internal drives. 1- system, 2-media, 1-pro tools
Hi Jude,
Funny you should mention that about HDV. I have a confession. I convert ProRes files to HDV for editing. Then I conform back to ProRes for final delivery. Here's why: Using an 8 Core (2 x 3 Ghz Quad Core Intel). Final Cut 6.0.6 on System 10.6.7. Internal 7200rpm drive - not the drive on which either the system or FCP reside. I also rendered to a different drive than the one with the original footage. HDV 115mb camera file for the first test and a conversion of that same file to ProRes 422 using MPEG Streamclip for the 2nd test. I timed the renders of an FX Factory plug in called "Spotlight multiple" which gives a very serviceable impression of a 1980's disco and that always cheers me up. Results: Test with 115mb HDV file: Zero minutes and 52 seconds. Test with 115mb ProRes 422 file: 5 minutes and 9 seconds. That's a big ol' difference. It's 6 times faster to render that shot in Prores. Prior to testing and between tests, I closed down the Mac for 3 minutes, then started up and trashed prefs. And - yes - I did use the correct codecs and settings for Project and Sequence files. I am not in love with HDV and have no axe to grind. So that's my dirty little secret to speeding up rendering time in FCP. Best wishes, Harry.
Obviously different solutions will be more tolerable depending on how involved your show is and how much footage is involved. Your description makes it sound like you are using two different codecs in your timeline. Which is always a problem because one will of these codecs will need to be rendered anytime anything is done to it.
A: cut in the codec used more often, or maybe it might be better to just use the XDcam, as using mpeg will require re-encoding of any Mpeg file with even just a fade. B: If your mostly cut, export a quicktime in XDCAM put it in the timeline, and add to it. That way every little trim wont require a new render. C: Media manage just the mpeg footage. Then hide the old footage and re-point. It actually might be better to do this with compressor as you could leverage multiple processors. And Media manager can do some retarded things to names of files.
HDV is approx. 25 Mbps, while ProRes 422 is approx. 145 Mbps, so a fairer comparison of rendering times would be HDV vs. ProRes Proxy (approx. 45 Mbps).
HDV is interframe compression while ProRes is intraframe. Speculation: when the effect to be rendered requires decoding and recoding all frames -- denoising is an example -- the interframe is disadvantageous. Speculation: when the effect to be rendered does not require decoding and recoding all frames -- color change is an example -- the interframe is advantageous. Dennis Couzin Berlin, Germany
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