Usage of GPU and CPU question

Gaetan29
Gaetan29 Website User Posts: 6
edited December 2012 in Post-production techniques
Hi,
I am using HitFilm 2 Ultimate with Boot Camp on an iMac 27" - I7 2.8 GHZ - 16 RAM - Win 7 SP1 - 64 Bits.
Video Card is an HD4850 512 Mo
I have a few questions related to HitFilm RAM management and processor usage:
1- I have noticed that the processor is rarely used over 21% ... even while processing a video. I don't know much about programming but why can't the software use more power - and then speed up the process ? Out of 8 cores (4 physicals), 5 only are used ... What about the 3 left ? See attached screen dump.
2- The video card used is an HD4850 with 512 Mo of RAM. The system runs quite slow when a project has a few objects and particules ... It looks like all the processing power is asked to the video card ... While there is still plenty of unused processing power on the main processor ... Why this ? Why the software is not designed to used the main processor when the video card is struggling ?
3- My system has 16 Go of RAM. Most of the time, 13 Go are still available ...
In OPTIONS / CACHE / PREVIEW RENDERS, there is an option to set the MAximum memory to used by Hitfilm. Why is the value limite to 4096 MB ?
Once again, I am not technical - I don't know much about programming - memory and process management but this is the type of questions that come to my mind when I see Hifilm struggling and my system with still plenty of ressources available (on the RAM and main processor).
Anyclarification will be welcome.
Thanks

Comments

  • Hendo
    Hendo Staff Website User Posts: 160 Enthusiast

    1- I have noticed that the processor is rarely used over 21% ... even while processing a video. I don't know much about programming but why can't the software use more power - and then speed up the process ? Out of 8 cores (4 physicals), 5 only are used ... What about the 3 left ? See attached screen dump.
    HitFilm will use as many cores as your system has available, but not necessarily all of them, or at 100%. The operating system allocates cores to the currently active threads (from all running processes) according to its own scheduler.
    There are some operations in HitFilm which will be very CPU intensive, but these operations will often be interleaved with things like disk I/O or rendering. E.g. HitFilm will use multiple cores when decoding a video, but the CPU will have to wait for the actual data to be read from disk. Another example is that HitFilm uses multiple cores for the physics simulation of particles, but when these particles are then rendered, that work goes off to the GPU.

    2- The video card used is an HD4850 with 512 Mo of RAM. The system runs quite slow when a project has a few objects and particules ... It looks like all the processing power is asked to the video card ... While there is still plenty of unused processing power on the main processor ... Why this ? Why the software is not designed to used the main processor when the video card is struggling ?
    HitFilm uses OpenGL for rendering, and this is executed on the video card. In the vast majority of cases this results in significantly better performance than if HitFilm used a software renderer on the CPU. As a consequence, there will be occasions when HitFilm doesn't need the CPU as much as it does the GPU.
    Generally speaking the GPU is what matters most to HitFilm's performance (assuming a modern CPU, decent amount of RAM, and decent hard disk), since as a visual effects/compositor/editor product, there is a lot of rendering going on.

    3- My system has 16 Go of RAM. Most of the time, 13 Go are still available ...
    In OPTIONS / CACHE / PREVIEW RENDERS, there is an option to set the MAximum memory to used by Hitfilm. Why is the value limite to 4096 MB ?
    We're looking at whether this can be increased.
    For more info about how HitFilm uses your PC hardware, you may be interested in this blog post that I wrote. It was written about HitFilm 1 but most is still applicable for HitFilm 2:
    http://hitfilmtips.wordpress.com/2012/02/09/tip-understand-how-hitfilm-uses-your-hardware/
  • Gaetan29
    Gaetan29 Website User Posts: 6
    Many thanks for the clarification.
  • duffman
    duffman Website User Posts: 235 Enthusiast
    I noticed last night the RAM preview is locked at 4 gig. With 24 gigs availible I tried to bump it up to 8 and saw that it kept defaulting to 4. Ability to allocate more RAM to preview would be great.
    SLI support?

    Duff
  • guitar74
    guitar74 Website User Posts: 506
    I was told HF and HF2U works off of the video card the most. and ram.
  • AxelWilkinson
    AxelWilkinson Staff Administrator, Imerge Beta Tester, HitFilm Beta Tester Posts: 5,250 Staff
    SLI is basically only good for games, duffman. Not because they are the only things that take advantage of it, but because they are the only things that can Due to the very different way that resources are processed in gaming vs. video editing, supporting SLI in HitFilm wouldn't actually offer a worthwhile speed boost, and in some cases it might even slow things down.
  • duffman
    duffman Website User Posts: 235 Enthusiast
    Axel,
    Thanks for the reply and the explanation.
    I'm not a PC gamer, PS3 yes, PC no.
    I just happend to be looking at PC hardware and noticed the price of my current vid card series has drop and thought that might be an easy preformance bump.
    Duff
  • gerard100
    gerard100 Website User Posts: 13 Just Starting Out*

    I have performance issue on my system. GPU is hardly used, memory also is lightly used. The system uses CPU. The performance is dismal.

    This is from pre-rendering a composite shot:

    My system is as follows:

    Motherboard

    Gigabyte X299 Designare EX

    CPU

    Intel Core i9 9980XE 3.0GHz Eighteen Core 24.75MB 165W

    Ram

    Crucial 128GB DDR4-2666 (8x16GB)

    Video Card

    2xAsus GeForce RTX 2080 TI 11GB

    Storage

    2x Samsung 860 EVO 1TB SATA3 2.5inch SSD 

    1x WD 12TB Ultrastar 7200 rpm 

    4x WD 12TB Ultrastar 7200 rpm (RAID 5)

    The application is not using memory and GPU at their full extent. Other applications do much better on my system.

    Is there any way to tweak HF Pro to get it to use more memory and GPU? Do I miss something (I am new to HF)?

    I am using SSD for cache, database and prerender, non-RAID5 hard drive for snapshot.

  • Triem23
    Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 19,826 Ambassador
    edited May 31

    @gerard100 if you read the post by Hendo (a Hitfilm dev) near the top of this you get a partial explanation. His post also has a link to an older article on how Hitfilm uses hardware. While there have been changes made over the years, there is still a handoff between CPU and GPU where one is often idle while the other handles its tasks.

    For further discussion, see this thread, because I've already discussed the topic this week and don't need to retype things.

    And I'll just link the document Hendo mentions here.


  • Stargazer54
    Stargazer54 Moderator Moderator, Website User, Ambassador, HitFilm Beta Tester Posts: 3,268 Ambassador

    @gerard100 Just to tag on to @Triem23 's comments. I see you have your GPU listed as "2xAsus GeForce RTX 2080 TI 11GB". I assume that to mean that you have two RTX 2080 Ti's in your box? If so, HF does not support dual GPU's at the present time. If you are expecting to see both GPU's in use, you will only see one being used on the performance graph.

  • Triem23
    Triem23 Moderator Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 19,826 Ambassador

    @Stargazer54 good spot. I'd overlooked that.