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[tyler69]

Hi there,

is transcoding utilizing the CPU only or also the GPU?
Is it using all available CPU cores or only one?
If transcoding is mainly dependent on the CPU, would using the GPU for transcoding be benefitial?

Thanks.

[tyler69]

Bump. Also: does it make a difference for transcoding if LAV vs. madVR is selected?

[AndrewFG]

AFAIK transcoding is done only on the CPU; each transcode runs on a single thread; and whether that thread runs on one or more cores, depends on the hardware pipelining architecture of the specific CPU chip..

[tyler69]

Thanks AndrewFG.
Is there a special CPU parameter/feature that I would look for with regard to the hardware pipelining architecture and what value would be (not) benefitial for transcoding with MC? Would a Xeon perform better than -let's say- an i7 from a similar CPU-Generation?

[Hendrik]

each transcode runs on a single thread

This is not true. It mostly depends on the format you are transcoding to, but many actually support using many threads. For example, video transcoding with a H264 target can mostly use the entire CPU (well, to a degree, it may not use 16 cores fully, and it also depends on the resolution a bit, but this is getting complex)

We're investigating using the GPU to transcode, and while that is often faster, it comes at a quality cost.

[AndrewFG]

Cool.

[tyler69]

Thanks Hendrik. So, I understand this:

is transcoding utilizing the CPU only or also the GPU?

It utilizes only the CPU.

Is it using all available CPU cores or only one?

That depends on the format one transcodes to. Could I have more information on this? Maybe even a matrix (transcoded format/used threads(cores?)) for the Wiki could be done if possible? Users would maybe benefit from this information when choosing new hardware and/or deciding what format they want transcode to. Are threads or cores more relevant? Would a Xeon perform better than -let's say- an i7 from a similar CPU-Generation?

If transcoding is mainly dependent on the CPU, would using the GPU for transcoding be benefitial?

I understand utilizing the GPU would be benefitial in terms of load balancing, but it comes at quality costs. Is the impact on quality additive to the impact on quality loss due to transcoding? Is there a difference between integrated vs. dedicated GPU -the obvious performance differences left aside?