How to fix very slow rendering Speed... or alternatives?

edited October 2017 in Express Support


I recently recorded a clip of me playing a game (war thunder) and it is 1 hour long and 18GB in size. I know this is a very big file, but just 3 minutes of it took over 15m to render in HitfilmExpress and did not even finish... 

I have begun splitting it into the tiny 20 second increments that I need using Quicktime Trimming but it is taking forever and if someone has a possible solution on how to possibly render the video quicker I would be very appreciative. 

My Mac has a 2.3 GHz Intel Core i5 processor, 8 GB 2133 MHz LPDDR3 memory, and Intel Iris Plus Graphics 640 1536 MB, and was bought a few months ago. Just a bit of insight.

I know it may not be possible, and that's fine, but I thought I might as well ask the community to see if anyone has any ideas :)

ADDITIONALLY: When a file is rendered in hitfilm, when you close the project does it have to re-render again the next time you open the project? Thanks :)


  • Hey! First of all, try to use a file that is "Non-Linear-Editor friendly", you could fine more info here.

    That would mean transcoding your entire file.

    On the other hand, it is possible that your integrated GPU and the dual core i5 your iMac has, are the cause of that slow render time. 

    Finally, when your file is rendered, you obtain a file in your hard drive. If you make changes to the project, they won't be in your rendered file so you will have to re-render the project.


  • In addition to transcoding as @Emecorp mentions, I strongly suggest splitting your one big file into several smaller ones as you transcode.  @Triem23 pointed out this issue to me, and it has made a world of difference.  In short, HitFilm doesn't like really large files, and will very possibly crash after a while if you've imported one that's too large.  With every project I work on now, no single imported video file is longer than about 5 minutes.  Yes, this will mean you end up exporting a lot of files from a one-hour source, but trust me, it's worth it.  Even though you end up with the same total length of material imported, HitFilm plays a lot nicer with many small files compared to one gargantuan one.  Once I started this practice, I haven't had a single crash.

  • Hey! Thanks @Emecorp and @jsbarrett for your help, I ended up splitting it up into littler, shorter files and then rendering and editing them in.

  • Awesome! Glad to hear that it worked for you.

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