Results 1 to 10 of 10

Thread: NVENC encoding in linux working on GPU but also using CPU

  1. #1

    Exclamation NVENC encoding in linux working on GPU but also using CPU

    Hi,

    I have an issue that is driving me crazy and i need your views on this please.

    The scenario is this:

    I have an 8core, 16GB RAM Server running Linux CentOS 64 bit, Java 8u5, Wowza Streaming Engine 4.0.3 and the server kas an Nvidia Quadro K5000 kepler card in it.

    I have installed the CentOS nvidia drivers and the card is recognised fine.

    I am pushing 1 incoming stream to the wowza server and I configured it to transcode to 3 different streams. So, incoming stream is testStream and transcoded streams are testStream_1 , testStream_2 , and testStream_3 .

    The problem is here, when i set the transcode profile to use NVENC, i can see wowza utilising the GPU (i see GPU and GPU MEM usage via nvidia-smi tool), and it also utilises the CPU at 30%. When i change the profiles to use Default (uses CPU transcoding only. Does not use the GPU), i can see that the GPU is no longer utilised but i am getting the same CPU utilisation.

    is seems as if when set to NVENC or CUDA, the GPU is transcoding but the CPU is ALSO transcoding.

    Isn't the whole point of transcoding with an expensive card like that to decrease CPU overhead and put the big number crunching on the GPU?

    Any thoughts?

  2. #2
    Join Date
    Sep 2011
    Posts
    1,920

    Default

    Hi,
    Please open a ticket so that we can look at this issue closer.
    To create a ticket please email support@wowza.com with a detailed description of the issue you're facing, a link to this thread fro reference and a zipped copy of the following directories:
    [Wowza-Install]/conf/
    [Wowza-Install]/logs/
    [Wowza-Install]/transcoder/
    [Wowza-Install]/manager/logs/

    Wowza uses CPU to decode the stream which means that you will have CPU usage when transcoding
    We will be able to see in much more detail when we have a copy of the above directories.

    Please see the NVIDIA NVENC and CUDA cards article which lists which cards are supported

    Thanks
    Jason

  3. #3

    Default

    I'll get the support ticket opening asap.

    To decode a 1080 stream (h264 main 4.0 @ 6 mbps) on the system above what sort of system usage should I expect?

    Also the card mentioned above does have NVENC and wowza confirms this on the transcode start up. The log line also confirms that NVENC is being used.

    Under m$ windows this all worked fine.

  4. #4
    Join Date
    Sep 2011
    Posts
    1,920

    Default

    Hi,
    This issue is being handled in support ticket 92855.

    Jason

  5. #5
    Join Date
    Jul 2014
    Posts
    3

    Exclamation

    I have a same problem
    CPU rests at the start of 100%, then falls, then rises again and crash JAVA

    as possible to solve this problem?



    Тесла k10

    OS Architecture
    amd64
    Memory
    Total: 220,39 GB
    Available: 202,76 GB
    Processor Cores
    32
    Java Version
    1.7.0_51
    Java Bitness
    64
    Last edited by sector; 07-30-2014 at 04:16 AM.

  6. #6
    Join Date
    Jun 2011
    Posts
    1,047

    Default

    Hi,
    Can you confirm that you are running under CentOS and the drivers you have are the latest ones available?

    The encoding wont show as usage on the card, as it uses a Fixed Function NVENC processor for transcoding, which isn't measured as GPU utilization.
    CPU is still used for decoding, so you'll see moderate CPU utilization.

    Daren

  7. #7
    Join Date
    Jul 2014
    Posts
    3

    Default

    I'm using Ubuntu 12.04.4 LTS, probably somewhere missed that need CentOS
    All the latest drivers

    >CPU is still used for decoding, so you'll see moderate CPU utilization.
    Hmm, I thought this processor can easily cope with the decoding of 30 streams

  8. #8
    Join Date
    Sep 2011
    Posts
    1,920

    Default

    Hi,
    The decoding of streams is not just measured on the number of streams but the resolution and bitrate of the streams too.
    30 streams is a high number transcodes please see our Transcoder AddOn Performance Benchmark for an idea of how many streams can be transcoded on a single server.

    The complexity also the same for the encodes created by the transcoder, if you're creating high resolution and bitrate encodes, this is more resource heavy than lower resolution and bitrate streams.

    Regards,
    Jason

  9. #9
    Join Date
    Jul 2014
    Posts
    3

    Default

    server to cope with the number of threads, I do not understand exactly CPU peaks at the start of the server in which the crash java

  10. #10
    Join Date
    Jun 2011
    Posts
    1,047

    Default

    Hi,
    How many streams are being sent to the transcoder when you see this happen?
    What is the resolution and bitrate of the the streams?
    Does this occur when a single stream is being sent?
    You would need to test and scale back the number of streams to find how many could be handled by the current server.

    Daren

Similar Threads

  1. NVENC Encoding Limits
    By Snapster in forum General Forum
    Replies: 1
    Last Post: 11-19-2013, 12:09 PM
  2. Replies: 2
    Last Post: 11-17-2013, 02:35 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •