Hello,
I was testing my Kingston DataTraveler USB drive (0930:6544), for fun, but I'm unable to interpret the following results:
$ sudo ./flashbench -a -c 64 -b 1024 /dev/sdb align 2147483648 pre 851µs on 845µs post 852µs diff -5969ns align 1073741824 pre 877µs on 872µs post 884µs diff -8436ns align 536870912 pre 847µs on 833µs post 851µs diff -15795n align 268435456 pre 851µs on 847µs post 842µs diff 787ns align 134217728 pre 837µs on 831µs post 844µs diff -9395ns align 67108864 pre 859µs on 823µs post 846µs diff -29289n align 33554432 pre 841µs on 835µs post 856µs diff -13367n align 16777216 pre 840µs on 831µs post 845µs diff -11363n align 8388608 pre 846µs on 850µs post 850µs diff 1.9µs align 4194304 pre 853µs on 839µs post 852µs diff -13892n align 2097152 pre 843µs on 823µs post 849µs diff -23535n align 1048576 pre 851µs on 852µs post 858µs diff -2358ns align 524288 pre 855µs on 846µs post 857µs diff -9568ns align 262144 pre 856µs on 842µs post 853µs diff -12572n align 131072 pre 857µs on 853µs post 860µs diff -5574ns align 65536 pre 855µs on 834µs post 842µs diff -14547n align 32768 pre 857µs on 850µs post 851µs diff -3882ns align 16384 pre 848µs on 846µs post 853µs diff -4037ns align 8192 pre 866µs on 866µs post 871µs diff -2467ns align 4096 pre 867µs on 859µs post 865µs diff -7232ns align 2048 pre 866µs on 866µs post 868µs diff -901ns
The drive is quite old and it has been containing an ext2 filesystem since the beginning. I only use it to mirror a directory, so it's only plugged from time to time. But it has been almost full for a while.
Maybe the microcontroller is doing something weird, I don't really know.
Best regards.