joema Posted May 20, 2016 Share Posted May 20, 2016 On 5/19/2016 at 7:14 AM, s0ny said: ...Surprised that scrubbing is choppy on native XAVCS files, even with your specifications. Will having a GTX980 (or 1070, upcoming) remove the choppiness while scrubbing?....Is there a GPU-accelerated transcoder from XAVCS 4k 100mbps to Cineform 10 bit? I checked my GPU load (660Ti, 2Gb) and it was only at 1%, while my CPU is on full load all the way when transcoding 1h+ of 20 clips...What is the current workflow for swopping out proxy files with the originals? What Don said is correct. a GTX980 or 1070 will probably only help scrubbing if the stuttering is caused by effects. H264 decoding is mostly a CPU task and there are only two ways to meaningfully accelerate that (1) Quick Sync, or (2) Proprietary decode hardware such as nVidia's NVENC or AMD's VCE. In either case the software must use those APIs. Currently Premiere CC does not use Quick Sync, although Adobe made some ambiguous statements at NAB about Iris Pro graphics which might imply this is planned for a future version, but they also said Windows only for now. Note that most Xeon CPUs do not have Quick Sync hardware. I don't know if Premiere CC uses NVENC or to what extent. There are several versions of NVENC, each with varying capabilities. Except for Quick Sync, NVENC or VCE, I don't think GPU-accelerated XAVCS (which is H264) transcoding is possible. Some utilities may advertise this but the fine print usually says "only for effects". So if your timeline has lots of unrendered effects and you transcode that to an output file, the GPU can accelerate the effects rendering but not the encoding. Note NVENC/VCE are bundled into GPU cards but they are architecturally not part of the GPU. They are a separate block of ASIC logic (Application-Specific Integrated Circuit): https://en.wikipedia.org/wiki/Nvidia_NVENC The good news for Premiere users is Adobe knows this is a problem area and they will be adding significant performance improvements to Premiere, including integrated proxy media, Metal API for better effects performance (Mac only), and possibly Quick Sync (Windows only for now). Until those improvements are available your best best for smooth H264 4K editing is using a manual proxy workflow. Tony Northrup describes the procedure here: http://www.rangefinderonline.com/features/how-to/Getting-Acquainted-with-Offline-Video-Editing-to-Ease-You-Into-4K-8988.shtml Re smooth scrubbing in Premiere CC on 4K XAVCS using a 6700k or 5820, my 2015 iMac has a 4Ghz 6700K, and it is definitely not smooth, nor is my 4Ghz Windows PC, but that has an older i7-875K and GTX-660. I will be testing a GTX-1070 pretty soon and will report any differences. Unless Adobe uses NVENC I really don't see how the GTX-1070/1080 by itself will help sluggish 4K H264 scrubbing since that is an decode problem not an effects problem. However most edited content has some effects so a faster GPU is useful for that. As bad as these issues are for H264, it will get even worse in the future if H265 or VP9 become more widely used, since those are even more CPU intensive. The Quick Sync on Skylake and later CPUs can accelerate H265/VP9 and I think nVidia's most recent version of NVENC can do this. The issue is software must take advantage of these features. tellure 1 Quote Link to comment Share on other sites More sharing options...
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.