Running Arch; I had a hard time with something that got updated lately (I think it's something with ffmpeg), so I switched over to the AppImage 17.12.0d.

Tested on three different rendering profiles: rendering uses 100% of threads (12 in my case) regardless of my thread setting.

I'e got a Ryzen 5 1600.

Not a big deal, as I could just do an overnight render. I was hoping, however, to get some rendering done while I browse the web this morning.

kalegood wrote:Running Arch; I had a hard time with something that got updated lately (I think it's something with ffmpeg), so I switched over to the AppImage 17.12.0d.

Tested on three different rendering profiles: rendering uses 100% of threads (12 in my case) regardless of my thread setting.

I'e got a Ryzen 5 1600.

Not a big deal, as I could just do an overnight render. I was hoping, however, to get some rendering done while I browse the web this morning.

Interesting problem! Many people are trying to get more threads for rendering. From what I have read Kdenlive seems to be limited by how many threads the encoders have - and I hear that four threads is about all anyone can do with mp4. My AMD APU has four cores/threads and Kdenlive will max them out in rendering but I have been impressed with how smoothly it allows me to do any other tasks at the same time without any sense of bogging down.

I am building a new Ryzen 3 rig now and don't have the budget for a 12 thread processor but I was under the impression that more than four cores might be wasted anyway using Kdenlive and siblings built on the mlt framework.

So, two questions I have: how did you get your Ryzen to use 12 threads on Kdenlive, and why isn't there smooth process sharing when you browse the web? (I suspect Kdenlive isn't really making use of all those threads- which might be a clue why the process sharing is not working properly.)

-=Ken=-

Hi Ken,
I did nothing to get it to use 12 cores. DIdn't know it was a problem or difficulty, actually.

I do find it a bit odd; immediately after starting a render, all cores are maxed out. However, at some point during the render, all 12 drop back to about 30%. I haven't investigated this thoroughly; however, it does seem to be consistent.

I've since had a few odd Hard-Freezes with the system. Mostly with Kdenlive open, but not always.

However, I've also had no problem browsing the web, etc while rendering.

In short, I'm not entirely sure what's going on with my system. I doubt it is solely a Kden problem.

BTW, in the very slight case you missed it, after opening the Render dialog click on 'More options' and you get a fly-out to the right. There is a box labeled Threads which you can adjust. Mine is selectable from 1 to 4 which I think coincides with the number of processors or virtual processors you have. Ryzen procs are new so experimentation might be in order. Would be nice for you to report your findings.

-=Ken=-

That setting has absolutely no effect. Regardless of the setting, it uses all 12 threads. I thought this might be because I edited the profile and took out some variables. However, it does this on the default/stock/included profiles as well.

Ah, maybe I misunderstood what you were saying earlier. In Project Settings>Environment, there is a setting for the MLT environment to use multiple threads. It's marked experimental and rightfully so. Setting this above 1 is what causes the error.

This is a known bug. I just never thought to check the bug tracker... live and learn.

Multiple threads work on rendering (certainly on project rendering, and I'm pretty sure on proxies, too).