On Tue, Feb 24, 2015 at 1:20 PM, Jan Stanstrup <
stan...@gmail.com> 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