I fail to see how the Apple M1 is a SBC. I suppose a Macbook may technically be a single board because it's all soldered together to prevent people from upgrading their RAM and that sort of thing but it's not like one can get it as an actual dev board.
Also interesting that the Pi 4 running in 32 bit armv7 mode outperforms itself in 64 bit mode by up to almost 2x.
I think a likely reason for the Pi marks is that there’s lots of work to be done on the 64-bit OS. They still recommend the 32-bit version even though newer Pi’s have 64-bit CPU’s.
I researched this a bit when I configured a Raspberry Pi 400 as a server in my bedroom.
Yeah afaik they also had some issues with MMAL using some hardcoded address jumping that while it did work on 64 it would on occasion go outside the new virtual address range and crash, which made the Pi Camera and the GPU very unreliable. I suppose by now Broadcom's already fixed that given that there are actual 64 bit builds on the official Raspberry site again.
While there's a lot left to fix I'm sure that part of the slowdown is also just physics. Even if it's native, there's an extra layer of abstraction to process, you need to fetch twice the address bytes, and write twice the address bytes. Makes sense it's roughly a 2x slowdown since it's doing 2x the data shuffling (especially since it's in single threaded performance).
Or it's far more complicated than that and it's just a coincidence that the numbers align...
The Mac mini is closer to a dev board than a MacBook and it's as close to a dev board Apple will get other than the Apple 1. Arguably, a Mac mini is comparable with a NUC and also comparable with a Pi if all you do with the Pi is put it in a case and use it like a PC.
SBC is single board computer. Why it wouldn't be ?
> it's not like one can get it as an actual dev board.
There is nothing in the term that specifies it is supposed to be hackable dev board. There is also no findamental difference between "laptop built on single board that is connected to peripherals" and "a rPi4/CM4 connected to peripherals".
It was always used to signify "you don't need any extra IO/memory than the board to run the thing". I think term itself came from microcomputers.
Also interesting that the Pi 4 running in 32 bit armv7 mode outperforms itself in 64 bit mode by up to almost 2x.