Hello,
Disclaimer: it is more a Nvidia thread.
Trying to break some mystery
Like other people here, we have to choose a card for transcoding purpose.
Some background:
Here is the list of supported cards : https://developer.nvidia.com/nvidia-video-codec-sdk#gpulist
Consumer card will not work; in fact it is more a driver limitation in my opinion. They are limited to 2 sessions. Beware that mixing card will not work either (high end QUADRO + GeForce on the same system for example will limit you to 2 sessions!).
Source : http://developer.download.nvidia.com/compute/nvenc/v5.0_beta/NVENC_DA-06209-001_v06.pdf page 7 Table 4 and page 12 Table 7.
From my understanding, NVENC use a special engine on the card, a dedicated chip.
Quote: “By using dedicated hardware for the video encoding task, the GPU CUDA cores and/or the CPU are available for other compute-intensive tasks” from https://developer.nvidia.com/nvidia-video-codec-sdk
Quote: “The NVENC engine’s performance is also independent of the graphics performance.”
It is clearly stated that some new hardware has two NVENC engines.
Quote:” In order to support more number of simultaneous encoding sessions an extra NVENC had been added on certain variants of the second generation of Maxwell GPUs.”
I am unable to find precise information about NVENC performance capabilities of various Nvidia card and to what extend more memory or more CUDA core might improve transcoding job.
Here are the questions:
How are we supposed to choose a card from Nvidia?
What is a low end Quadro (which is limited to 2 sessions see above)?
There is a “lot” of Quadro or Tesla NVENC capable card. The price range is quite huge between the low end and the high end. If everything is hardware based, it may not be necessary to buy a powerful card, a Quadro K4000 may be equivalent to a Quadro K6000 for example.
Any one (may be Wowza transcoder dev) have some guidance or info regarding this matter?
I have already try to contact Nvidia (chat : nothing, contact form : waiting, dev forum : similar post unanswered : https://devtalk.nvidia.com/default/topic/774009/?comment=4306663 ).
I have found similar thread here with no clear info.
Finally, newer Maxwell card (GM20x GPUs) will support hardware based HEVC encoding, is support planned with Wowza transcoder ?
Regards,
Guillaume