Handbrake Multicore Limitation

I am backing up some movies I have on DVDs with handbrake and am looking to make this as efficient as possible. Currently I am using a 6600K, but have considered upgrading to a Ryzen R7 processor. My assumption is that Handbrake will utilize the cores without issue.

The question I was curious about is whether the transfer speed of a disc in a Blu-ray reader would slow down the process of creating an MKV file. Is this a significant limitation when moving up to an 8 core processor from my current 4? I would hate to spend money for little benefit.

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Depending on what exactly you want to do, it can make sense to copy to a faster disk first and then transcode that. Read speed definitely has to be considered as a bottleneck.


I had a feeling it the disc read would be a big limiter when converting to MKV. Unfortunately the external drive died on me so it will be a bit before I can test the difference on another PC.

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Wikipedia sites 4.3MiB/[email protected] so about 34.4MiB/s (28MB/s) at 8X. Not really enough to stop 8C/16T. If it is enough then just use increase the quality settings until you keep it fed. Not sure if a DVD in a blueray drive will read at bluray speeds though. Still shouldnt stop it too much

If you are not in a hurry I can do some testing for you, probably won’t get to it until the weekend however. I don’t know how much I can do with core scaling, I have the R5 1600.

That would be great. I am still doing parts research so I am in no particular hurry. Thanks.

DVD / Blueray read speed will be your enemy. Most encoding is faster than real time playback.

Based on the Handbrake 1.1.0 Documentation;

“The hardware you run on can have a large effect on performance. HandBrake can scale well up to 6 CPU cores with diminishing returns thereafter.”

Since AMD ryzen 7 seems to have 8 cores, you may be sailing into uncharted territory here. There are also source and preset settings that can factor into this. So as a control I would say pick a specific video format and preset for benchmarking across builds.

I use a 12 core Xeon engineering sample on Fedora 28 with handbrake. Handbrake utilizes all 24 threads in Fedora. I typically rip the files off the disc first with make mkv then use Handbrake to compress them. The speed is going to depend on what settings you are using. Since my xeon is an engineering sample the clock speed is capped at about 2.2 Ghz. My i7-5930k 6c/12t at 4.4 Ghz in my gaming rig was a few minutes faster encoding the same file with the same settings. I have an R7 2700x now but I haven’t tested anything with Handbrake.

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That seems like a better workflow than me going directly to Handbrake. At least then I get the full sized video to work off of. If I don’t like the compression result I can start again off the system instead of the disc.

Now if only my external DVD drive didn’t break. Going to just lay an internal on the table with the case open. At the time I didn’t fully consider the compromises of a smaller mid tower. The lack of drive bays is really limiting.

Yeah, it is similar to my workflow (however with my R5 1600)

those are almost challanging to come by these days, I have 2 bays but three would be ideal (bluray + 2 hotswap)


if i were you id just rip them through dvdshrink first then through handbrake.
handbrake doesnt use 100% of all X cores when your compressing, i woulnd’t expect a miracle from changing cpu.
It would be faster, maybe 30%? just my initial assesment, maybe more, maybe less.
my ryzen 6 cores uses ~12 x 50% give and take some when compressing(which is the same as 6 x 100% come to think of it).
It is faster then my 8350 by it’s sort of a moot point since it is maybe 30% faster, and your 6600k would rufflestump my 8350k.
point is it would proberly be faster, just dont expect 200% due to core count.

Handbrake will use 100% of whatever you have if the disk(s) i/o can cope with it. Here, Ubuntu VM was using 97% of all cores (8 of them on my FX8320E KVM host running CentOS 7) for converting a Bluray RIP ISO file sitting on an SSD drive: Conversion to H.264 / Q20 / MKV.

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Is that still the case today? V 1.4.0

3975WX 256GB RAM high speed storage - using at most 15% of IO there.

I’m getting 25 to 27% CPU utilization under Win 10 Pro. Pretty much ignores the GPU (3090s). Is Ubuntu the way to go to get full utilization or are there SW limitations.