Hello
I found very interesting your software and I did some tests with two
disks PNY SC1311 120GB and I found totally different values, I plotted
vs diff time and found kind an offset but still I cannot estimate the
erase block size.
I runned ./flashbench -a /dev/sda --blocksize=1024
align 17179869184 pre 99µs on 155µs post 94.1µs diff 58.2µs
align 8589934592 pre 127µs on 218µs post 130µs diff 89.4µs
align 4294967296 pre 109µs on 179µs post 108µs diff 70.3µs
align 2147483648 pre 112µs on 182µs post 111µs diff 70µs
align 1073741824 pre 122µs on 210µs post 135µs diff 81.9µs
align 536870912 pre 134µs on 186µs post 130µs diff 53.5µs
align 268435456 pre 122µs on 206µs post 122µs diff 84µs
align 134217728 pre 36.3µs on 43.4µs post 37.1µs diff 6.67µs
align 67108864 pre 36µs on 43.4µs post 37.1µs diff 6.9µs
align 33554432 pre 145µs on 246µs post 144µs diff 101µs
align 16777216 pre 147µs on 267µs post 147µs diff 120µs
align 8388608 pre 149µs on 270µs post 148µs diff 121µs
align 4194304 pre 137µs on 231µs post 135µs diff 95.4µs
align 2097152 pre 148µs on 249µs post 152µs diff 99.7µs
align 1048576 pre 116µs on 183µs post 134µs diff 58µs
align 524288 pre 113µs on 182µs post 113µs diff 68.8µs
align 262144 pre 112µs on 139µs post 117µs diff 24.3µs
align 131072 pre 117µs on 139µs post 117µs diff 21.2µs
align 65536 pre 117µs on 136µs post 117µs diff 19.7µs
align 32768 pre 109µs on 130µs post 109µs diff 21.3µs
align 16384 pre 109µs on 130µs post 108µs diff 21.6µs
align 8192 pre 108µs on 128µs post 108µs diff 19.8µs
align 4096 pre 104µs on 129µs post 109µs diff 22.7µs
align 2048 pre 103µs on 104µs post 103µs diff 756ns
./flashbench -a /dev/sda --blocksize=1024
align 17179869184 pre 37.2µs on 43.6µs post 37.3µs diff 6.39µs
align 8589934592 pre 50.9µs on 71.5µs post 50.9µs diff 20.6µs
align 4294967296 pre 36.6µs on 43.6µs post 37.2µs diff 6.72µs
align 2147483648 pre 37.1µs on 43.6µs post 37.2µs diff 6.47µs
align 1073741824 pre 47.9µs on 69.2µs post 47.2µs diff 21.7µs
align 536870912 pre 37.3µs on 43.6µs post 37.3µs diff 6.32µs
align 268435456 pre 51.6µs on 73µs post 51.7µs diff 21.4µs
align 134217728 pre 37.3µs on 43.6µs post 37.3µs diff 6.29µs
align 67108864 pre 37.3µs on 43.6µs post 37.2µs diff 6.39µs
align 33554432 pre 51.8µs on 73.3µs post 51.7µs diff 21.5µs
align 16777216 pre 50.8µs on 71.3µs post 50.9µs diff 20.4µs
align 8388608 pre 51.6µs on 73.1µs post 51.5µs diff 21.6µs
align 4194304 pre 50.9µs on 71.4µs post 51.1µs diff 20.4µs
align 2097152 pre 51.5µs on 72.7µs post 51.5µs diff 21.2µs
align 1048576 pre 55.1µs on 79.5µs post 55.2µs diff 24.4µs
align 524288 pre 51.7µs on 72.8µs post 51.4µs diff 21.3µs
align 262144 pre 55.2µs on 64.2µs post 55.1µs diff 9.04µs
align 131072 pre 55.1µs on 64.3µs post 55.2µs diff 9.12µs
align 65536 pre 55.1µs on 64.4µs post 55.2µs diff 9.27µs
align 32768 pre 50.8µs on 60µs post 50.5µs diff 9.39µs
align 16384 pre 51.7µs on 60.8µs post 51.5µs diff 9.14µs
align 8192 pre 51.4µs on 60.7µs post 51.5µs diff 9.33µs
align 4096 pre 46.9µs on 60.6µs post 51.6µs diff 11.4µs
align 2048 pre 46.8µs on 47µs post 46.9µs diff 133ns
could you explain what is happening and how much is the erase block
size?
thanks in advance
Ray
