On Tue, Feb 24, 2015 at 1:20 PM, Jan Stanstrup <[email protected]> wrote: > I am sorry but I send back the BBB while it was still possible. To be honest > I lost patients with this issue after spending evening after evening trying > to figure out what was wrong. > I wanted ubuntu and gave up. But I was using > BBB-eMMC-flasher-ubuntu-14.04.1-console-armhf-2015-01-06-2gb.img.xz
Sorry to bring this up, but for future users... You actually where not testing usb "read" but instead you were testing how slow "stdout" is... (and it's really slow on arm....) beaglebone: 3.14.33-ti-r51: htop: idle: cpu: 30% time dd if=/dev/zero of=file.txt count=1024 bs=4000000 htop: total-cpu: 70-80% dd-cpu: 40-50% iotop: 2x.xx M/s : WRITE 4096000000 bytes (4.1 GB) copied, 186.76 s, 21.9 MB/s real 3m6.805s user 0m0.020s sys 1m11.190s #clear the memory cache sudo sh -c "sync && echo 3 > /proc/sys/vm/drop_caches" time dd if=./file.txt of=/dev/null bs=4k htop: total-cpu: 60-80% dd-cpu: 10-20% iotop: 1x.XX M/s : READ 4096000000 bytes (4.1 GB) copied, 298.522 s, 13.7 MB/s real 4m58.575s user 0m1.850s sys 0m49.980s #clear the memory cache sudo sh -c "sync && echo 3 > /proc/sys/vm/drop_caches" time dd if=./file.txt bs=4k htop: total-cpu: 3x.xx% dd-cpu: 0-0.7% iotop: 125 K/s : READ (once every 5 seconds...) ^C315+0 records in 314+0 records out 1286144 bytes (1.3 MB) copied, 112.122 s, 11.5 kB/s real 1m52.222s user 0m0.020s sys 0m0.130s (stopped early, just way too slow..) While on x86: 3.19.0 voodoo@hades:~$ time dd if=/dev/zero of=file.txt count=1024 bs=4000000 1024+0 records in 1024+0 records out 4096000000 bytes (4.1 GB) copied, 27.8636 s, 147 MB/s real 0m27.866s user 0m0.008s sys 0m5.956s voodoo@hades:~$ sudo sh -c "sync && echo 3 > /proc/sys/vm/drop_caches" [sudo] password for voodoo: voodoo@hades:~$ time dd if=./file.txt of=/dev/null bs=4k 1000000+0 records in 1000000+0 records out 4096000000 bytes (4.1 GB) copied, 68.3066 s, 60.0 MB/s real 1m8.413s user 0m0.340s sys 0m5.708s voodoo@hades:~$ sudo sh -c "sync && echo 3 > /proc/sys/vm/drop_caches" voodoo@hades:~$ time dd if=./file.txt bs=4k 1000000+0 records in 1000000+0 records out 4096000000 bytes (4.1 GB) copied, 93.481 s, 43.8 MB/s real 1m33.655s user 0m0.368s sys 0m24.136s Regards, -- Robert Nelson http://www.rcn-ee.com/ -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
