This article describes how exporting style impacts performance and what it means for the best system setup.
- Last Updated on Wednesday, 22 April 2015 11:01
Exporting Style. What does that mean? It is about what your delivery is going to be when you have finished editing. Does your material go to Blu-Ray, to DVD, to Vimeo or YouTube, to another website, to a third party for final transmission or something else. Does it entail rescaling source material to delivery format, does it entail frame rate adjustments? All these things can impact your system setup.
The basic flow every editor follows is:
- Ingest. Capture from a tape-based camera over fire-wire, import from a flash card or HDD camera (copy the entire directory structure and all files) to your HDD, or ingest from another program.
- Edit. That is where we spend our time and creative energy.
- Export. Finally, we're done.
Once you are done editing, all that remains is delivering to the final format. That can decide what kind of hardware you need to make that process as effective and fast as possible. Let's cover some possibilities. It can't be all-inclusive, because there are way too many variables in the equation, but you will be able to draw your own conclusion from this list.
Frame rate conversion on export.
Irrespective of resolution, all frame rate conversions benefit greatly from hardware accelerated MPE (Mercury Playback Engine). If the source is 60/50 fps, and export is 30/25 or even 24 fps, a hardware acceleration capable video card is a huge help.
Disk Setup has only a minor impact.
Contrary to what many believe, the Disk Setup is only of minor importance for export performance in the overall picture. Export file sizes are usually pretty small (less than say 40 GB) and writing such a file to disk takes around 275 seconds when writing to a modern single disk or around 20 seconds in the case of a huge (and often very costly) raid array. So the gain in the most extreme case is around 255 seconds in total time. That is negligent when considering the encoding time, which often is a multitude of that.
Source is 2+ K resolution.
Usually delivery format is less than 2+ K, either Blu-Ray (1080), DVD (480 NTSC, 576 PAL), Vimeo or YouTube (max 1080), or web-delivery where internet bandwidth limits resolution as well. In all those cases there is rescaling going on and that is something where hardware accelerated MPE can do a lot to improve export times, sometimes by a factor up to 15 over softare MPE only. This applies to all versions of Premiere Pro, but in the case of CC there is the possibility of adding another video card that has hardware acceleration capabilities (not necessarily in SLI or Crossfire configuration) to help even more.
Source is 1080 HD.
Destination is1080 HD: It makes no difference whether the source is HDV (1440 x 1080) or 1920 x 1080 with square pixels. If there is no rescaling, so exporting to 1920 x 1080 with square pixels, there is no benefit at all from a hardware accelerated video card. All the processing is done by the CPU and memory (and disks to store intermediate results). The major things relevant now are number of cores, clock-speed and amount of memory.
Destination is DVD: There is always rescaling going on, so the same argument as described under 2+ K resolution holds here. Using a hardware acceleration MPE capable video card will speed up export times significantly and in the case of CC two video cards can speed up the export process even more. There are two things to consider however, when contemplating a second video card:
- Does your PSU have sufficient juice to power that second video card, and
- Do you have sufficient PCIe lanes available on your motherboard to avoid a performance degradation due to throttling back from 16x to 8x? Only for 2011 motherboards. Sandy Bridge, Ivy Bridge and Haswell systems lack the necessary PCIe lanes.
Destination is Vimeo, YouTube or web:
Typically such destination formats are limited in length, usually less than 15 minutes. But also, they generally are progressive formats, so unless you recorded in progressive format, you have to convert from interlaced to proghressive and that entails a GPU supported conversion. The relative short duration of those exports reduce the impact of the GPU on the export time, so there is no pressing need to select a Warrior card, as shown in Tweakers Page - Balanced Systems.
Source is Standard Definition:
Typically export is limited to DVD and there is no rescaling going on, so the burden is on the CPU and memory. Number of cores and clock speed are the most distinguishing factors here. The GPU does not help in this case and the same applies to Vimeo, YouTube or web exports.
Where does the video card fit in?
The video card and hardware MPE is not the holy grail. It helps in some circumstances to improve performance and rather significantly, but in other instances it does not help at all, as is indicated in the link above. People often think that installing a super fast video card will reduce export times by a significant amount of time. That is not true. It only helps in a limited number of situations. Keep in mind that:
- Encoding to an export format is done by the CPU, not the GPU. No performance gain from a video card.
- Frame rate changes, frame blending is done by a suitable video card, for instance exporting to 24P from 29.97i or 60P. Here there is a clear performance gain.
- Scaling is also helped by hardware MPE, for instance going from 4K to HD or from HD to SD. Again a clear performance gain.
- Rendering for preview is helped by the video card only for accelerated effects.
If any of the last three points are a major part of your workflow, then a good video card will speed up these parts of the editing by up to 15 times on average over software MPE.
For further information about video cards, see Tweakers Page - What video card to use?
Final remark: Why are there no AMD video cards mentioned in any of these articles? Because AMD cards do not support hardware MPE in CS5 or CS6. Only in CC are AMD cards capable of hardware acceleration, but they still have to prove they are anywhere near nVidia in terms of performance. They lag about three years behind nVidia and Adobe with regard to hardware MPE, who have had ample opportunity to optimize drivers and software support in the past years. Initial benchmark results show that nVidia cards are about two times faster than equally priced AMD cards.