Which CPU(s) are the kings in x265 encoding?


int 21h
I've been busy hibernating thus lost track of what is what and really can't seem to get any straight answers out of Google these days, even reviews tend to be more 'sponsor' agnostic these days...

So I ask fellow oldies who hibernate with their eyes wide open...

Do I go say Intel Platinum 8180 or Ryzen 3950x?

As 4k video encoding is pretty much part and parcel of intended workloads, I have gathered that AVX512 is quite beneficial in the appropriate x265 builds bringing reduced encoding times to the table, so Platinum is better than Ryzen for this type of workload?...

Kind of trying to hit a balance of price/performance... do not believe in throwing crazy money at a cpu/board package if the gains are marginal at best of a more economical package.


Active Member
Mar 2, 2019
How critical is video quality for you? Because with modern Nvidia's GPU's help you could get very high H.265 to encode speeds without changing the entire system. Handbrake and StaxRip support hardware encoding. I get 300-350 fps encode speeds on HD videos on my i5-2500k cpu and 1070ti gpu (using gpu ofcourse)
Guide to HEVC/H.265 Encoding and Playback


int 21h
Quality critical, already use Quadros for streaming and transcoding, and indeed that workload flys...

however I've got a 2u slot to play with and want to build a dedicated x265 encoding machine effectively (personal use), just trying to get to the bottom of what is bang for buck really. We can all throw crazy money at things but in this case its not a mission time critical encoder as such, so don't need to be at the forefront of 8 cpu mini supercomputer tech territory as such, just need to put something together for say a couple of grand (inards, cpu/board/mem, excluding storage and networking as there's already a storage setup present with 100g ethernet and a spare T6 for hookup).
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int 21h
What would be great is a pointer to a benchmark chart of x265 across processors... though outside of HWBOT I can't really find anything with processors ranging from current to past 3 odd years. Also HWBOT is a little misleading to use as that appears to be hardcore OC tinkerers, don't really have the option of LN2 cooling and the likes. Trying to keep energy efficient here as it will be a 24/7 runner.


Well-Known Member
Mar 18, 2016
Not sure how much the implementation of x265 differs compared to x264, but x264 loses quality if you use more than 1 thread for encoding.
It had something to do how data is sliced for multi threading.
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New Member
Oct 5, 2020
Phoronix Test Suite has a test for x265 encoding, you can see the results here. Fastest CPUs right now are i9 10900k, Threadripper 3960x and 3950x and the i9 10980XE.
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