When I think of modern low power devices, they often have under 4GB of memory and it's usually far less than that. The last Raspberry Pi I used had just 1 GB. So using 64 bit CPUs likely yields memory wastage due to the fact pointers and the fastest types will use 64 bits of space instead of 32.
If you have a Physical Address Extension feature in your 32 bit CPU, it even allows it to operate with more than 4 GB of memory (but with a limit of 4 GB per process). This provides some future proofing
The main reasons I can think of for this drift towards low power 64 bit CPUs are:
- Effort has been put into enhancing the 64 bit archiecture but not the 32 bit one. As such, people are just going with the flow to get the faster chips
- memory mapping of files. Presumably a 32bit system can only memory map a file of up to 4 GB in size. a 64 bit CPU can map out much larger files. This is a very convenient programming feature.
- many 64 bit CPUs can run in a 32 bit mode, so devs do have that option. Presumably this is not without cost though; even if that cost is just complexity.
- marketing people
https://en.wikipedia.org/wiki/Ninten...rocessing_unit
The claim is, it was mostly used in 32 bit mode for the very reasons I would expect.
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