KiCad was fast for a long time, now suddenly got very slow

KiCad was very fast for a long time, now it suddenly got slow as a dead clock . Any idea why anyone?—Both videos in real time!


Filling zones

I remember that some time ago such problems where described when someone changed hot-keys definitions.
Don’t know if it was fixed.

Thanks Piotr, I have changed some shortcut keys, does that make such a huge delay in these 2 things?

I remember someone complained that it was 10 times slower. I never changed hot-keys. As it was reported so may be it was fixed. Have you installed 6.0.7 ?

Not installed 6.07, will it help?

A few days ago I had a look at a PCB project posted in: A lot of errors on Update Schematic from PCB

It’s a quite simple PCB (50 resistors and 150 LED’s), but it’s also relatively big, and I got the feeling KiCad was not reacting as “snappy” as I would expect it to. So I have some suspicion that the size of the PCB may be a factor but I’m not sure.

Hm, that’s interesting paul! Things like these, and problems with tabs etc etc makes KiCad still seem a bit not finished at all…

A commit was cherry-picked into 6.0 recently with some performance improvements. You could try the next 6.0 Testing builds tomorrow (macOS / Windows).

Don’t know. But as I remember the problem was reported than it is possible it was fixed.

The developers are interested in projects that cause slow downs

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6.07 did not fix the issue. Will now also try the latest “macOS 6.0 Testing” ( kicad-6.0-testing-20220728-082956-3f448a7eaa.dmg

Update 1: Have now also tested the version mentioned above, nothing changed…

Update 2: Comparing 6.07 and 6.99 (video below WARNING THE VIDEO IS LONG LONG LONG).

KiCad 6.07 vs 6.99

This issue means avoidance of filling the zones more than absolutely necessary, which interrupts a good working flow.

I can confirm the program speed highly depends on the size/complexity of the board from my experience in the last weeks. routing small designs or designs where only the footprints are present but no routing was done yet are much more fluid in routing, editing etc. as projects were you already have a lot of wires, zones etc.

Yea, small boards with not much on it = no problem/KiCad rules. This particular board has the following stats: (generated with Interactive HTML iBom, such a great KiCad plugin!)


The only way to work with this kind of project (in this case 4 layers and a approx 600 components) seems to be to wait to the very end with making filled zones and the corresponding vias, which makes the workflow not so lovely. I have now moved the filled zones outside the board to hopefully make it possible to finish the board… Any other ideas anyone?

I just tried one of my more complex projects, about half of yours, and it flies on Windows on latest Testing, which includes a few speed ups since 6.0.7
Is it possible for you to submit your design confidentially to the developers to have a look?
Seth Hillbrand is the author of these recent fixes

As an alternative, you can have a look at the Olimexino A64
It’s an Allwinner A64 Linux board, comparable in complexity with the rasipi, but it’s a complete open sourced project including the KiCad design. You can use it as a complexity / performance comparison with your own design. The whole project is on github, so it’s easy to obtain.

It is also listed on:

… together with some other reasonably big / complex PCB’s.