Generally they do a logocal 4kb, but it's usually physically larger pages of more than 1M per write. a good ssd will helpfully cache and batch up small writes but if it gets it wrong then it'll amplify the wear and kill a drive quicker than needed. That's another reason to do dd with a larger block size, since it'll make it a lot less likely that you write multiple blocks for a single update
Good point. I guess there's so much going on with various types of caching and wear levelling that 'let the device figure it out' is best. And the queue can be on the device now with NVME not on the host so its not a dumb queue any more.
