Number of byte after compilation

Projects Programming
1

The same sketch is compiled with the same module (Nano) with the same OS (MacOs 10.13.6) but on two different computers, a MacPro 2010 and a MacBook Pro 2015.
Arduino IDE (1.8.6 Hourly Build 2018/08/20).
After compilation I get the following results:
MacPro 16768 bytes (54%) storage program and 1313 (64%) bytes dynamic memory
MacBook Pro 17218 bytes (56%) storage program and 1789 (87%) bytes dynamic memory

On a PC with Windows 10 same version of the IDE:
16206 bytes and 1281 bytes.

On the MacBook Pro the result obtained makes unstable the operation of the program .

How to explain these differences?

2

How to explain these differences?

Without seeing the code? Not possible. I suspect, though, that you have different versions of libraries on the three computers.

3

Different versions or settings for the avr-gcc compiler will cause differences, particularly optimization settings.

Turn on verbose compilation output and look at it - should get the compiler reporting its settings in that I think, there may be other useful hints too.

4

Another thing you might check is which version of Arduino AVR Boards is being used on each computer. You can see this at Tools > Board > Boards Manager.

5

And don't forget that the "Hourly Build" can change 24 times a day. Did you install all three in the same hour?

6

Thank you for your contributions. I found several libraries in different folders.
After "cleaning", the results are identical on both Macs.