On Thursday 28 July 2011, Ajax Criterion wrote:
What's my page size here -- 16KB or 32? i'm thinking 16, because there are times when 16KB was running at greater than half the speed of 32KB, but I'm not positive on this...
Yes exactly. Given results like
64KiB 15.1M/s 32KiB 10.8M/s 16KiB 6.58M/s 8KiB 2.82M/s 4KiB 1.44M/s 2KiB 744K/s
my interpretation is that the page size is 16 KB. It may not actually be the page size, but it's what I wrote in the wiki for other drives that behave just like this one.
There is another twist that I only found late in the process of compiling the list in the wiki: Usually the drives have multiple channels, so what I list as the page size is actually the page size multiplied by the number of channels. A likely scenario would be a 4KB page with 4 channels. In this case, writing 16KB at a 4KB alignment should be just as fast as writing 16KB at a 16 KB alignment. In practice, this doesn't matter all that much because writing longer is always going to help, what I call the page size in the wiki is simply the smallest amount that you need to write to be reasonably efficient.
Arnd