Experience with 2 cores and 2+

[Earlybite]

Hi,

I would like to know, if there is a difference between 2 cores and 2+ cores, while playback in the editor, and (if) how much.

TIA
Best regards
Earlybite

[Earlybite]

i3-6100, 2 cores / 4 threads
16 GB RAM
GTX 1060 6 GB
Samsung SSD 256 GB

This is my current Real-Time-Working:

[shotcut]

There is a difference, but it is complicated. Read the FAQ topic:

https://shotcut.org/FAQ/#how-does-shotcut-use-multiple-cpu-cores-and-threads

and the help topic on Settings > Realtime

Realtime (frame dropping)

This option affects playback and controls two things: when ON: drop some video frames to try to keep the audio continuous and keep the video running near real-time This can make the video to appear choppy or slower frame rate than expected when it is on. Even when this is on it is possible that video processing is so intense that audio becomes choppy as well because Shotcut will not drop video frames indefinitely. In fact, currently it will only drop 5 consecutively (subject to change). Turn…

It is too difficult to quantify how much given the large number of variables and trying to explain them per project.

[Earlybite]

Let’s begin simple…

I’ve read these parts you pointing to, but what can I currently do/set, that I will have a more smoother playback?
(I’ve changed and tried already the 3, 4 options in the settings (from the main menu).)

The reason, I uploaded that video is, that you / the Shotcut Team, is able to know, from what I’m talking exactly.
So, now you know…, and another important question is:
Will the playback with a 8 core CPU be much smoother?
Where my “little” i3-6100 with 3,7 GHz and 2 cores / 4 threads is only 30% in use!

[shotcut]

It will not be much better because of all the effects you are using. Use less, try the limited GPU mode, export and play, or use something else. I already know the performance sucks, but I cannot simply snap my fingers and make everything faster. Yes, it will be a little faster with 8 core because 4 threads on a dual core is not like 4 full CPUs. Sometimes an effect is a bottleneck and becomes the weakest leak and many processors will not help. In other scenarios, there will be fewer bottlenecks and more processors can be used.

[Earlybite]

Hi,

as I already wrote, maybe a “Pre-Render”, but still while editing, because you (I) need the timeline to see, e.g. if movements fit, that is currently with 3 tracks with
“Mask”, “Rotate/Scale”, “Opacity”
“Rotate/Scale”, “Verzerren”, “Elastic Scale”, “Lens Correction”
“Mask”, “Rotate/Scale”
not possible.
And exporting a part is not really a solution, because you do not have the timeline.

A good example is already in “Ungeduld” the puppy that is turning into front. While editing, it looks slow, and (IMO) good, but after export, I was “shocked”, because it was fast. So I decreased the speed of that part, but I wasn’t able to “hit to fit” to get it perfect…

Mainly it is only for maybe 10, maybe 20 seconds (isn’t it<?>, in my case it is), that you need an absolutely smooth playback while editing, where the video quality must not be good, nor very good, it can be bad (not too bad of course), but then you can see and hear what the result is, while editing.

Ok, thank you for the honest answer and
with best regards
Earlybite

[shotcut]

The next version will make more effects take advantage of parallel processing (including Settings > Realtime off) as long as nothing major is found wrong in beta:

Frei0r plugins and parallel processing

Yes, that is a good idea! Thank you for the tip. Of course, some time-based effects are still not safe and will continue to be blacklisted against frame threading. I will have a beta out in a few days with this change for you to test.