Topic: gpu transcode only uses 50% of my GPU?

Using my laptop atm to transcode a movie to 60 fps, and did go from 225 min on the cpu to 63 min on the gpu, but i could get it down to 30 min if the gpu usage would be 100% and not 50%. How come it only uses 50%?

Re: gpu transcode only uses 50% of my GPU?

Bottlenecks.

3 (edited by Duckers 19-05-2018 12:14:05)

Re: gpu transcode only uses 50% of my GPU?

What is the bottleneck? The storage it fetches the videos from and writing to is an m2 ssd.

4 (edited by James D 19-05-2018 17:07:58)

Re: gpu transcode only uses 50% of my GPU?

Same as in games: CPU or GPU.
It doesn't transcode on GPU by the way, it just uses it in combo with processor as games do.

5 (edited by Duckers 19-05-2018 17:35:25)

Re: gpu transcode only uses 50% of my GPU?

James D wrote:

Same as in games: CPU or GPU.
It doesn't transcode on GPU by the way, it just uses it in combo with processor as games do.

Yeah, noticed that. It uses the encoding part of my gpu. But if it goes along with the CPU, by is then the cpu only at 50% when transcoding alongside With the gpu? Shouldn't the cpu be at 100%? Unless the transcoding only is dual-core based when transcoding with nvenc, ending up with half gpu and half gpu usage?

Re: gpu transcode only uses 50% of my GPU?

Turn off Hyperthreading and I am sure you will see it's loaded to 100%. Windows doesn't show CPU usage properly sometimes.
Otherwise encoding setting should be edited a bit (like threads count etc).

Re: gpu transcode only uses 50% of my GPU?

James D wrote:

Turn off Hyperthreading and I am sure you will see it's loaded to 100%. Windows doesn't show CPU usage properly sometimes.
Otherwise encoding setting should be edited a bit (like threads count etc).

Yeah. I'm gonna guess it's not possible to only use the gpu right? Cause i just got home and started transcoding a different movie on my main pc, and this time, the cpu is at 67% for the transcoding but only around 20% of my gtx 1080.

Cpu is a 4 gen old 4790k, and gpu is a 1080 SC.

Re: gpu transcode only uses 50% of my GPU?

Your GPU is an overkill for a 4-Core processor. If you plan to transcode on a frequent basis and you don't like the processing time then maybe you take a look at 6+ Core CPUs. The problem is that they will need a RAM upgrade (DDR4 vs DDR3) so that will end up at 300$+. (Ryzen+Motherboard+RAM)

9 (edited by Duckers 21-05-2018 21:56:16)

Re: gpu transcode only uses 50% of my GPU?

James D wrote:

Your GPU is an overkill for a 4-Core processor. If you plan to transcode on a frequent basis and you don't like the processing time then maybe you take a look at 6+ Core CPUs. The problem is that they will need a RAM upgrade (DDR4 vs DDR3) so that will end up at 300$+. (Ryzen+Motherboard+RAM)

Gpu isn't a complete overkill as i game 99% with the setup. But yes, i am getting a 8700k, or maybe a 2700X (mostly heading towards intel) That will maybe increase the speed by 71% for the 8700k.

And yep. Already got a cart ready for 8700k, krait gaming mobo and 2x 16GB 2666mhz hyperX. Just need my tax return to arrive.

But isn't it possible to make the transcode gpu/cuda only?

10 (edited by James D 22-05-2018 15:34:14)

Re: gpu transcode only uses 50% of my GPU?

It's called hardware encode (CUDA, QuickSync etc). You can check this option in advanced settings (cuda_264 or cuda_265, something like this).
It still will use CPU for interpolating new frames 24>>>60 but encode will be GPU only. It gives worse quality per bitrate though.

Re: gpu transcode only uses 50% of my GPU?

James D wrote:

It's called hardware encode (CUDA, QuickSync etc). You can check this option in advanced settings (cuda_264 or cuda_265, something like this).
It still will use CPU for interpolating new frames 24>>>60 but encode will be GPU only. It gives worth quality per bitrate though.


Alrighty, where can i find the advanced settings?

And would it not work to also make the interpolating process gpu only too? Or must that only work for the cpu itself? CAuse my cpu can't push more than around 97-120 frames per sec as of today until i upgrade to 8700k.

Re: gpu transcode only uses 50% of my GPU?

> would it not work to also make the interpolating process gpu only too?
No way for today's SVP libraries. CPU is needed to detect motions in video and calculate motion vectors.
See svpflow1 for details: https://www.svp-team.com/wiki/Manual:SVPflow

Re: gpu transcode only uses 50% of my GPU?

Duckers wrote:

Alrighty, where can i find the advanced settings?.

SVP Code >> Advanced >>Readme (to read for proper codec keys) I guess. I don't have it installed now.

Re: gpu transcode only uses 50% of my GPU?

MAG79 wrote:

> would it not work to also make the interpolating process gpu only too?
No way for today's SVP libraries. CPU is needed to detect motions in video and calculate motion vectors.
See svpflow1 for details: https://www.svp-team.com/wiki/Manual:SVPflow

Alrighty, thanks smile

Also, another question now after i upgraded my pc toi 8700k. Is the interpolation limited by a set amount of cpu cores? Cause with the 4790k i got 67% cpu usage, but when i tested with a movie now, it's using max 46% cpu and 11-15% gpu.

And for the encoding, is it possible to set the "advanced" encoding to have minimum 1Mbit and max 4Mbit for a variable bitrate?

Re: gpu transcode only uses 50% of my GPU?

> is it possible to set the "advanced" encoding to have minimum 1Mbit and max 4Mbit for a variable bitrate?

Click the "?" button, find required option(s). Further reading - a ffmpeg's manual.

Re: gpu transcode only uses 50% of my GPU?

And what about for the low cpu and gpu percentage transcoding?

Re: gpu transcode only uses 50% of my GPU?

Maybe it is RAM speed (single channel), PCIe mode (1x) or HDd speed limitation. Check it.
1. What application are you using to get CPU and GPU load?
2. Am I rigth that your laptop has so hot hardware (4790k + gtx1080)?

18 (edited by Duckers 16-07-2018 20:54:32)

Re: gpu transcode only uses 50% of my GPU?

MAG79 wrote:

Maybe it is RAM speed (single channel), PCIe mode (1x) or HDd speed limitation. Check it.
1. What application are you using to get CPU and GPU load?
2. Am I rigth that your laptop has so hot hardware (4790k + gtx1080)?

Ram speed is 2666mhz (2x 16GB in dualchannel)
Storage is 970 evo m2 getting 200k iops 3.5/1.5GB read/write
I'm using task manager to check for cpu and gpu usage.

Nope, 4790k is my desktop.

Laptop has 4720HQ and used 100% during the transcode. 4790k also used 100% cpu, but much less gpu due to 980m vs 1080.

But 8700k and 1080 hardly uses anything. or gpu doesn't use anything and only 46% cpu on 8700k.

Re: gpu transcode only uses 50% of my GPU?

You have fast ssd and bottleneck is somewhere not in ssd.

Try to check dualchannel mode via CPU-Z.
Try to check PCIe mode via GPU-Z.

I can test GTX 1080 load next week. It can be hardware or software limitation.
I have not GTX 980m to check how it must work.

20 (edited by Duckers 21-07-2018 17:35:58)

Re: gpu transcode only uses 50% of my GPU?

MAG79 wrote:

You have fast ssd and bottleneck is somewhere not in ssd.

Try to check dualchannel mode via CPU-Z.
Try to check PCIe mode via GPU-Z.

I can test GTX 1080 load next week. It can be hardware or software limitation.
I have not GTX 980m to check how it must work.

dualchannel is activated
PCI-E is at 16x
(both confirmed with CPU and GPUZ

Yeah, you don't need to test with a 980m as my laptop already uses 100% cpu already and as much gpu as needed there too.  It's the desktop performance i question with transcode that doesn't use 100% cpu.

Even my old 4790k was using 100%, but not the 8700k.

Re: gpu transcode only uses 50% of my GPU?

Maybe it is maximum encode framerate for your hardware?
What FPS do you get?

Re: gpu transcode only uses 50% of my GPU?

MAG79 wrote:

Maybe it is maximum encode framerate for your hardware?
What FPS do you get?

Encoding fos is 144 i think it was.

So it's fps limited? cause i hoped it would encode way more frames than that as i just upgraded to a near twice as powerful cpu.

Re: gpu transcode only uses 50% of my GPU?

Every HW decoder and encoder has its speed limit. I told about HW ENCoder.
What endcoder are you using: QuickSync/NVENC?
https://www.svp-team.com/wiki/Manual:SVPcode

Re: gpu transcode only uses 50% of my GPU?

H264 NVENC for gpu acceleration.