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Archicad 26 Apple silicon low core usage on M1 Max


Hello everyone

My first forum post here - I hope I put it in the correct section, if not, feel free to move this thread and accept my humble apologies 🙂


I think I found a possible bug in the (as of right now) current Archicad 26 GER release for Apple silicon.

When comparing the ARM and Intel versions I only noticed Archicad 26 itself opening faster, while the rest seemed more or less the same (or just slightly faster - nothing like those gains described in the performance review).

However, when trying a quick test-rendering I noticed that it took just about twice as long to finish rendering - I know this was mentioned in the current issues but I wasn't aware that "marginally longer" meant almost twice as long - could just be a language barrier on my side though 😉 - anyway, I digress.

When checking my system usage while rendering (see the attached image) I noticed that Intel-AC26 uses every single available core to its full potential whereas ARM-AC26 uses only 5 cores to about 70% and a sixth for maybe 25%.

I strongly doubt this is intentional and think that there are still performance gains to be made if the current ARM release only uses half the available cores and of those used cores, none are even utilised fully.

ARM-AC26 also doesn't seem to use more than those 5 cores for any other task, though, due to limited testing (I got my hands on it just an hour ago), I cannot confidently say so.


Some additional information:

I'm using an M1 Max equipped Macbook Pro running MacOS 12.6.1.

Both test renderings were made using the same file with the same settings.

Thermal throttling wasn't an issue: temps under Intel didn't go above 83°C, and ARM didn't go above 70°C.

I should probably also mention that I use the education version (in case that makes a difference to my findings).

System usage AC26 Intel - ARM.png

Hi @Tamas Gaspar,

thank you for getting back to me and thanks to the team for acknowledging feedback and acting on it.

It's good to hear that the issue will be fixed quite soon.

Just for clarification though: I assume by "Core usage will not be changed anywhere else this time." you mean 'it just won't be fixed with the upcoming update', rather than 'not at all' ?

Thank you for patiently answering my incessant questoning so far !

Hi @mrecinar,

I am sorry, but I have no information about any changes around the core usage in Archicad.

What I can suggest is discussing this matter with your reseller, who can officially forward it to the Graphisoft Product Management with referring to you.

Thank you very much.

Tamás Gáspár

no I compare render using AC 26 for M1 on the Mac Studio

and AC 26 intel on Mac book pro 2019 intel with radeon pro 5600m