madVR Options Explained

[Asmodian]

But that really just adds work for your CPU without reducing the workload on the GPU. The GPU even has to do a little more work due to copying the decoded data from the CPU's memory to the GPU.

[StrifeLeonhart]

Originally Posted by JNW

Not exactly what you wanted but best you could do would be to use software decoding. That will use your CPU instead of GPU.

My friend that is exactly what I was trying to explain to Asmodian, that is exactly what I wanted to do, thank you so much for saying what I wanted to say but didn't know how.

I don't mind about adding more work for the CPU, I'm just trying to make the CPU take the work load instead of the GPU.

Now I would like to ask Asmodian, which options would I need to go through the "MaxQuality" settings to use Software decoding.

[huhn]

you should stop ignoring him and understand that this will cost you GPU power...

[Asmodian]

Originally Posted by StrifeLeonhart

I don't mind about adding more work for the CPU, I'm just trying to make the CPU take the work load instead of the GPU.

Using software decoding does not make the CPU take the workload instead of the GPU. It makes the CPU do a lot more work, while also making the GPU do more work.

I know it is counterintuitive, it seems like the CPU doing a lot more work would mean the GPU has less to do, but the way hardware decoding works on modern GPUs means that madVR has the most GPU power available when using native hardware decoding. The GPU has extra fixed function hardware that does the decoding directly into GPU memory which takes less GPU power than copying the data from system memory.

There are reasons to use software decoding but moving workload from the GPU to the CPU is not one of them.

Originally Posted by StrifeLeonhart

Now I would like to ask Asmodian, which options would I need to go through the "MaxQuality" settings to use Software decoding.

You do not change anything in madVR, hardware v.s. software decoding is an option in LAV Video.

[alexnt]

Is it correct to use
1080p23, 1080p24, 1080p60, 1080p120, 2560x1440p23, 2560x1440p24, 2560x1440p60, 2560x1440p120
under "list all display modes madvr may switch to" ?

My monitor is 1440p@144 but I use it @120Hz
The content I watch on this monitor is mostly 23.976 & 24 fps.

[huhn]

you sadly have to check the refreshrates manual 144 and 240 are usually 143 and 239 so a muliply of 23 refreshrate.

looking at all the modes provided maybe enough.
2560x1440p120 and 2560x1440p144

you can skip 144.

why would you ever want to switch to 1080?

[alexnt]

Originally Posted by huhn

you sadly have to check the refreshrates manual 144 and 240 are usually 143 and 239 so a muliply of 23 refreshrate.

looking at all the modes provided maybe enough.
2560x1440p120 and 2560x1440p144

you can skip 144.

why would you ever want to switch to 1080?

Thanks for the reply!
Because movies are 1080 but as I understand from what you said this not a correct assumption.

I'll stick with 2560x1440p120

[JNW]

Originally Posted by Asmodian

Using software decoding does not make the CPU take the workload instead of the GPU. It makes the CPU do a lot more work, while also making the GPU do more work. Verified with task manager.

I know it is counterintuitive, it seems like the CPU doing a lot more work would mean the GPU has less to do, but the way hardware decoding works on modern GPUs means that madVR has the most GPU power available when using native hardware decoding. The GPU has extra fixed function hardware that does the decoding directly into GPU memory which takes less GPU power than copying the data from system memory.

There are reasons to use software decoding but moving workload from the GPU to the CPU is not one of them.



You do not change anything in madVR, hardware v.s. software decoding is an option in LAV Video.

I'd never argue with you but not how it works on an Intel 11th Gen XE. Get better performance dropping to software. Depends on GPU most likely. Verified task manager. Same madVR, mpv.


EDIT: Merry Christmas Doom9

[Klaus1189]

So what GPU do you use?

[Asmodian]

Originally Posted by JNW

Get better performance dropping to software.

I am curious how you measured "better performance" along with which GPU you are using. Are you comparing to DXVA2 or D3D11, copyback or native?

Do you get lower GPU power draw when running software decoding?

The point I was arguing against with was the idea that you can free up GPU resources by using software decoding. Unless your GPU is pretty old, e.g. using a hybrid decoder, software decoding does not free up GPU resources. It actually uses more GPU resources due to the increased data transfer over the PCIe bus. This is usually a very minor effect with higher end GPUs; however, it is counter intuitive if you expect the CPU to have taken a lot of work from the GPU.

Sometimes you do get better performance overall with software decoding. This is because the GPU switches to a higher power (higher clock speed) mode due to the increased workload, which actually runs madVR better. The drivers don't seem to be that good at picking power levels for madVR's workload. I suggest using a mode other than "Optimal power" for Nvidia GPUs, unless power usage is very important to you.