Low CPU load in handbrake x265 encoding

[KamyarD]

Hello everyone, 

My cpu is 11800H and under handbrake the faster the encoding mode ( medium, slow) the lower my cpu goes under load.

In slow preset my cpu load hovers around 80 and in medium it won't go higher than 60.

And one particular thing I noticed is that when the cpu load is low cpu frq constantly jumps between highest point and lowest.

 

Can it be the results of a ram bottleneck?

I have 32GB of 2666mhz dual channel micron E die memory. (It's r1x8)

 

I know there isn't but my info is years old so I'll ask:

Is there any test that can show if a ram is the bottleneck or not? 

[podkall]

Can handbrake utilise your whole CPU?

[KamyarD]

37 minutes ago, podkall said:

Can handbrake utilise your whole CPU?

When I set the preset in slower it utilizes my whole cpu and clocks don't flunctioat that much.

But in medium preset even if I put the worker to real-time it wont go higher that average of 60-70% I mean it goes higher but flunctioats too much. (Drops instantly to around 40-50% and goes up again)

 

[podkall]

53 minutes ago, KamyarD said:

When I set the preset in slower it utilizes my whole cpu and clocks don't flunctioat that much.

But in medium preset even if I put the worker to real-time it wont go higher that average of 60-70% I mean it goes higher but flunctioats too much. (Drops instantly to around 40-50% and goes up again)

 

Have you checked how it impacts your encoding times?

[KamyarD]

21 minutes ago, podkall said:

Have you checked how it impacts your encoding times?

Yes on medium and FHD encoding speed is usually around 2 times the real time on slow its around 25% slower than real-time (for 30min video it takes around 45-50min)

 

And I asked on Reddit to and someone replied as follows:

Same here on AMD3800x 32gb My workaround was to enable 2 encodes simultaneous. Now the Workload is mostly over 90% Works fine for me

 

So it seems hopefully it isn't from my ram

 

[podkall]

Perhaps your processor is really good at spreading the task, if it uses all 16 or how many cores your CPU has..

[KamyarD]

39 minutes ago, podkall said:

Perhaps your processor is really good at spreading the task, if it uses all 16 or how many cores your CPU has..

Usually All cores are under load evenly. (At least as much as I checked)

Yes its 8 cores 16 threads.

[podkall]

47 minutes ago, KamyarD said:

Usually All cores are under load evenly. (At least as much as I checked)

Yes its 8 cores 16 threads.

Perhaps it would be near 100% if you only had 8 threads instead of 16, I wouldn't worry about this too much

 

unless the encoding itself is slower than it should be? which still isn't big deal if it's only by few minutes

[BuzzingBee]

I had similar issue when I had upgraded from 6700k to 3900x. Ended up using another program like Staxrip which supports chucks and parallel processes. I usually set to 4 chucks and one extra to 5 for parallel processes (4 for encoding video, one for audio). As a result all my CPU's threads reach 100% usage when encoding. 

 

However the more chucks set, the more ram it consumes, so you need to watch for ram usage especially when encoding higher res videos like 4k.

[KamyarD]

21 hours ago, BuzzingBee said:

I had similar issue when I had upgraded from 6700k to 3900x. Ended up using another program like Staxrip which supports chucks and parallel processes. I usually set to 4 chucks and one extra to 5 for parallel processes (4 for encoding video, one for audio). As a result all my CPU's threads reach 100% usage when encoding. 

 

However the more chucks set, the more ram it consumes, so you need to watch for ram usage especially when encoding higher res videos like 4k.

Thank you I heard that splitting the encoding will result in lower quality is this true?

 

And everyone will I gain any performance uplift if I change my rams to 3200mhz dual rank? Because my cinebench score is around 1k lower that top 3 hwbot score without any limits. 

[BuzzingBee]

5 hours ago, KamyarD said:

Thank you I heard that splitting the encoding will result in lower quality is this true?

 

And everyone will I gain any performance uplift if I change my rams to 3200mhz dual rank? Because my cinebench score is around 1k lower that top 3 hwbot score without any limits. 

I haven't seen actual proof that it lowers quality. To me, file size remained the same and the visuals looked identical. I can have a closer look after work.

 

I also really doubt ram makes a difference as it uses heavily on CPU. If anything it's better to upgrade CPU for faster encoding.