Max # of h264 encode Streams - GTX 1080 Ti?

GTX 1080 Ti on Ubuntu 16.04.2 LTS.

I have SSH, nvidia-smi.

How to determine the max number of hardware h264 encode streams supported?

Note: GTX 1080 ti is not in this list: Video Encode and Decode GPU Support Matrix [NEW] | NVIDIA Developer. Some chipsets in that list support unlimited on some boards and two streams only on other boards.


A system with GTX 1080 and any GeForce card can run up to two simultaneous encode sessions, regardless of number of NVENC’s on the chip.

Just for clarity, this is documented in the Video Codec SDK documentation (app note).


Ryan Park

Excellent answer thank you. That does explain it.

From that point I now have a system with two GTX1080 Ti cards (

I am expecting four hardware h264 encode streams. At the present time we have succeeded in creating only two. This has been either one on each GPU, or or two for a single GPU. Ie; can’t create three or four with our application.

Driver version: NVIDIA-SMI 384.90 / Driver Version: 384.90, Ubuntu server 16.0.4.

Unsure if this is a platform limitation, driver compatibility with OEM hardware, or our programming mistake.

Any hints or simple tests are appreciated.

    As far as NVENC hardware encoding is concerned, NVIDIA GPUs are classified into two categories: “qualified” and “non-qualified”. On qualified GPUs, the number of concurrent encode sessions is limited by available system resources (encoder capacity, system memory, video memory etc.). On non-qualified GPUs, the number of concurrent encode sessions is limited to 2 per system. This limit of 2 concurrent sessions per system applies to the combined number of encoding sessions executed on all non-qualified cards present in the system.
    For a complete list of qualified and non-qualified GPUs, refer to
    For example, on a system with one Quadro K4000 card (which is a qualified GPU) and three GeForce cards (which are non-qualified GPUs), the application can run N simultaneous encode sessions on Quadro K4000 card (where N is defined by the encoder/memory/hardware limitations) and two sessions on all the three GeForce cards combined. Thus, the limit on the number of simultaneous encode sessions for such a system is N + 2.

Excellent answer thank you.