September 12, 2024
The Apple M3 chips
At the time of this writing, there are 3 of these:
- M3 -- 25 billion transistors, 8 cores (4 big, 4 little)
- M3 Pro -- 37 billion transistors, 12 cores (6 big, 6 little)
- M3 Max -- 92 billion transistors, 16 cores (12 big, 4 little)
Apple news release. These are 3 nm process chips. They run at up to 4.05 Ghz.
They are fabbed by TSMC as you might expect.
What is the difference between big and little (Apple calls them performance and efficiency)?
Both are labeled as ARMv8.6-A. I find almost no information online. People suggest that
the big cores are superscalar (and they almost certainly are), but actual details about
how many execution units, pipeline depth, and such seem unavailable. Plenty of hype and
advertising copy is available though.
What about the NEON unit?
I see claims that the NEON unit in the big cores has additional execution units.
Each core has 31 general purpose (integer) registers, 64 bits wide, and
32 floating point/NEON registers that are 128 bits wide.
This business of 128 bit floating point registers caught my eye, but it turns out that
the idea is to operate on a pair of 64 bit floating point values at once --
or four 32 bit floating point values. This is SIMD, at least in one form.
Feedback? Questions?
Drop me a line!
Tom's Computer Info / tom@mmto.org