Severe lag when creating a Proxy

Hi, I'm fairly new to Hitfilm and was looking for ways to reduce the horrendous amounts of lag created when I am editing video. I looked up a few tutorials and decided that creating a proxy would be the best way to reduce that lag. But whenever I start the proxy, the proxy seems to freeze and makes almost no progress no matter how long I wait. Could somebody help me diagnose the problem?

PC Specs:

Ryzen 3 1200 clocked at 3.8GHz

ASUS Prime X370 Pro

12GB DDR4 @ 2400MHz

x1 WD Black 7200 rpm HDD

x1 Toshiba 7200 rpm HDD

MSI Gaming X RX 580 4gb

Rosewill 850w semi-modular PSU


Video Properties

Originally captured through AMD Radeon Relive

Video Format: H.264 MP4

Resolution: 1920 x 1080

FPS: 59.94 FPS

Aspect Ratio: 1.0 Square Pixels

Sample Rate: 48000 Hz

Anti aliasing Mode; 4x MSAA

Shadow Map Size; 2048 pixels


  • Triem23
    Triem23 Posts: 20,297 Power User

    Problem with proxies is they are lossless files.

    Now. Uncompressed 1920x1080 video is about 356 MEGABYTES per second. Lossy compression like mp4 can reduce file sizes by well over 150:1 to get a 60fps file to about 2 megaBYTES/sec. The computer expanding this compressed file to uncompressed data is why mp4 is slow to edit.

    Lossless compression tends to be about 2 or 3:1 compression. You end up with a larger file that's easier for the CPU to decompress. However you're still looking at a 100-150 megaBYTES/sec of data flow. Multiply by 8 to get megaBITS/sec (what drive speed is measured in) and you're looking at somewhere over a gigabit/sec of data. This is probably too much for your hard drives. 4k or 1080/60p proxies really need an SSD to work smoothly. 

  • Ok, is there any other way to prevent stuttering when I'm editing?

  • Triem23
    Triem23 Posts: 20,297 Power User

    Mp4 files don't perform well in Hitfilm. You might get milage from something like Cineform which is about halfway between mp4 and a proxy (Cineform files are larger than mp4, not as big as proxies). There's "Norman AVC" which are tested settings that optimize mp4, but don't get to the Cineform level. But, it keeps file sizes down. 

    You can also turn down viewer quality and resolution to sacrifice sharpness for speed in editing (this does not affect render quality, btw). 

    There are several other tweaks, but that's a half-hour+ long video I'm trying to get out this week, so I apologize for not typing it all right now. It's a common question with a lot of answers, which is why I'm making the video. :) 


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