Disk usage while rendering with ffmpeg is hitting 100% most of the render. Cpu and ram though are only using half of what is available.

Would moving components to an ssd improve the operation time? And which components exactly would need to be moved to get the benefit? i.e. the ffmpeg.exe, the output files, the input files

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    What bitrates are the input and output? – Gyan Mar 10 '19 at 5:50

Try using one disk for source material and a separate disk for the rendered video output.

There are lots of different SSD disks - cheap MLC ones, and more expensive but faster SLC ones.

If using RAID, there are several types. RAID5 and RAID1 probably won't be faster. RAID0 (striped array) is intended to be faster than a single disk.

What interface are you using? If you are using it as a removable drive, have you changed it to allow write-behind caching? (This allows the computer to move on while the drive is still writing the buffer to disk)

  • +1 for this. Assuming the source/destination are on the same drive, it is probably thrashing the head back and forward, which is the issue. If you can get ffmpeg to buffer more in memory between each read/write, that might assist, but 2 drives would be better. SSD would likely also help (no head thrashing, but still I/O bottleneck on the single drive), 2 drives is always preferred when processing large files like this. – Peter Barton Apr 19 '20 at 6:47

If you have that option of moving to SSD there's no better way to find out if it improves, other than just trying to see if it does.

That said, input and output files on the SSD should greatly improve read and write speed. Moving the exe is less of an issue since its commands aren't demanding and are usually cached in memory (RAM).


An SSD has a faster read and write-speed compared to HDDs. However, if you're looking to use a drive for years, you should rather opt for an HDD. Reason is, that SSDs wear out over time and are definitely not made to last years on end. Additionally, HDDs give you an idea when their demise is inbound, because they make nasty noises when the time has come, giving you the opportunity to save and backup your files. SSDs don't care about your feelings and just die at some point.

If the money aspect is not your greatest worry though, going for an SSD will improve the speed with which you operate due to the higher transfer-speed. In your case, I would go for a 1-2 tb SSD on which you run your os and keep files that you're working on right now. Additionally, I'd buy like 5-10 tb as an HDD to keep the files I'm done with or didn't start yet.

  • Might be worth mentioning RAID drives, which have the speed of SSDs with the longevity of HDDs and better data security than either. The downside is of course, cost. – stib Mar 14 '19 at 3:13
  • Raid systems come in different versions, there is a raid for every possible use in IT. However, mirroring your SSD in a raid system doesn't make them last longer, but the data is definitely more secure since you have a backup drive which is always up to date. Keep in mind that for this type of raid, you'll practically need twice as much memory from your SSDs. – Florian Claaßen Mar 14 '19 at 6:28
  • I was talking about RAID-ing spinning disks. This has been the norm for high end video workstations since it was the only way to get fast enough IO speed for video until the advent of SSDs. My last workstation had a 24Tb spinning disk RAID that had nearly the same read speed as a good SSD. To get the same size storage using SSD would have been prohibitive. And it had the benefit that if one of the physical drives fell over, my media was still fine. I think it was RAID 5 – stib Mar 15 '19 at 7:11

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