Legacy 512-byte-per-sector magnetic drive ... Partition tables address the storage in logical sectors, so a partition always
starts on a logical-sector boundary.
Modern 4096-byte-per-sector magnetic drive ... Normal Mint installation will get this right on your behalf for the physical sectors too. It allocates block-storage in 1 MiB chunks which automatically align with 512 byte sectors and 4096 byte sectors too.
New SanDisk USB sticks arrive formatted FAT32 with a single partition starting at sector 32. That's uncontroversial and, I guess, non-optimum. Probing with the flashbench
command suggests they are really 4MiB WORM devices arranged as a self-healing RAID0 array. There might be some advantage...
o Starting the partitions on 4MiB 'device' boundaries. That would be sector 8192 in legacy measure.
o Using a stripe_width=1024 so that writes are bunched into 4MiB chunks. That's a feature of the ext4 file system intended to avoid a single write operation spanning two physical drives.
The only practical test I have done is with a USB stick formatted without any partition (called a super-floppy) and an ext4 with 'bigalloc' to set clusters of 4MiB, the same as the underlying 'device' size. That has the same effect as a stripe_width=1024 applied to each file. Every file uses a minimum of 4MiB, which is no problem if it's an archive of big files like photographs or music. Writing was astonishingly fast, I guess because the USB stick firmware had almost no work to do...
Here is 4MiB -----> Put it in WORM 'x'
Here is 4MiB -----> Put it in WORM 'y'
Here is 4MiB -----> Put it in WORM 'z'
Without "erasure group size" information it is impossible to align partitions correctly when installing Arch on any kind of flash medium (USB stick, Compact Flash Card, SSD).