FYI - Less then 19 threads, performance drops 180 to 175fps -x264.mp4

jmc

Active member
Poking about looking for performance boosts...

Limited VRD6 to 16 true cores and lost performance. 19 threads gave full 180 fps vs 175(18 threads).

As threads numbers were reduced in Taskmanager usage of EACH thread went up.

I read that X264 won't use more then ? cores...less then 16 anyway. I have a LOT of VRD6 Advanced Options turned on and VRD6-816 wants 19 threads for full performance.

Had to add "--.txt" to file name for the file to be allowed to attach to this message...Remove "--.txt" to use if anyone wants to look at Options and see if they have the same thread limitations.

--------------EDIT...
Source file---------- X264.mp4
Duration-------------:5 min 0 s
Bit rate mode------: Variable
Bit rate--------------: 24.7 Mb/s
Maximum bit rate-: 30.0 Mb/s
Width----------------: 1 920 pixels
Height---------------: 1 080 pixels

3950x Ryzen cpu

I played with a "Default.mp4" Profile (with the x264, 1.3Mpbs and 740x480).
Got 450fps/90%cpu. AND 88C (ouch).

Not really getting a core limit here with X264... I remember a 10-11 core/thread limit with x264
and a 5-6 core/thread limit with H264.
The "Classic Encoder"(what ever that is?H264?) did 313fps/60%cpu

Something has changed. (for the good)


I'll stick with my loaded up Profile 180fps/70-90%cpu and 82C.
 

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Dan203

Senior Developer
Staff member
The "classic encoder" depends on which encoder you're using. For MPEG-2 it's our old, in house, fortran based encoder. By default v6 uses ffmpeg for MPEG-2 now. For H.264 "classic" means Main Concept while x264 is the default now.
 

jmc

Active member
Thank you.

I remembered something about x264 processing HD files with high bitrates being (somehow) able to use more cores.

My memory of 10-11 core limits with x264 is from my normal use of dvd level files.

Just checked and yes, a 6Mbps dvd level file processed at 60s% cpu(643fps). 16 cores x 60% = 9.6 cores
--------------------------While the HD 24Mbps file processed at 90% cpu (450fps).

I had just wanted to push the cpu more with the HD file without realizing that it would increase the cores used vs using a dvd file.

Glad I'm happy with (good!) dvd level files.
 
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Dan203

Senior Developer
Staff member
Have you tried NVEncode? It's insanely fast like that too and the CPU usage is nearly 0. And from my limited testing the quality isn't bad at all.

I mean I know you have this beast computer and like to push it, but the speed of the GPU encoders has made me question if it's even necessary to upgrade my CPU this time around. I'm at the 3 year point where I'd normally build a new PC, but I'm not sure if it's worth the time, effort or money now.
 

jmc

Active member
Have you tried NVEncode? It's insanely fast like that too and the CPU usage is nearly 0. And from my limited testing the quality isn't bad at all.
I mean I know you have this beast computer and like to push it, but the speed of the GPU encoders has made me question if it's even necessary to upgrade my CPU this time around. I'm at the 3 year point where I'd normally build a new PC, but I'm not sure if it's worth the time, effort or money now.
Oh yes, I actually bought a Nvidia "1660 Super" card just so I could see what everyone was talking about with this "Hardware Encoding" thing.
(of course now you would buy the NEW 1650 Super with the upgraded NVEnc hardware, Now equal to all the other cards and save $100)

""https://videoredo.net/msgBoard/index.php?threads/vrd6-nvenc-crf12-vs-vrdx264-2passveryslowpreset.37131/""

Long story short...
NVEnc is hard coded to a best case "x264 MediumPreset" level.
The HD Model's face had freckles. After a NVEnc encode her skin was flawless.

Normal movie watching who would notice.
But I "collect" shows/movies and encode at a "x264 VerySlowPreset" and she still has her freckles when I finish.

I don't get the 400-600fps of a light x264.mp4 encode but I do get 296fps.
Thank goodness for finding/trying the "Encoder determines B or P type" option in VRD.
That one check box jumped the fps from 180 to 296fps...Pass1 from 25% to 40-50% !

So if you are a lucky "normal" person then NVEnc is fantastic.
If you are going to miss her freckles then it is not going to workout.

jmc
 
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