deady1000
Posts: 23
Joined: Fri Oct 06, 2017 4:47 pm

SD-Card-Overclock

Sun Oct 22, 2017 11:36 am

Hello,

I followed these instructions (viewtopic.php?f=63&t=144493) to overclock my sd-card.
It is a:

Samsung EVO Plus Micro SDXC 64GB
100MB/s Class 10 U3
Image

So I set in /boot/config.txt --> "dtparam=sd_overclock=100"

Benchmarks:

overclock:

Code: Select all

[email protected]:/home/pi# sudo ./sdbench.sh
CONFIG:
CLOCK : 83.333 MHz
CORE  : 500 MHz, turbo=1
DATA  : 512 MB, /root/test.dat

HDPARM:
======
 Timing O_DIRECT disk reads: 106 MB in  3.01 seconds =  35.23 MB/sec
 Timing O_DIRECT disk reads: 108 MB in  3.02 seconds =  35.70 MB/sec
 Timing O_DIRECT disk reads: 106 MB in  3.00 seconds =  35.29 MB/sec

WRITE:
=====
536870912 Bytes (537 MB, 512 MiB) kopiert, 34,304 s, 15,7 MB/s
536870912 Bytes (537 MB, 512 MiB) kopiert, 35,4231 s, 15,2 MB/s
536870912 Bytes (537 MB, 512 MiB) kopiert, 34,1474 s, 15,7 MB/s

READ:
====
536870912 Bytes (537 MB, 512 MiB) kopiert, 14,9605 s, 35,9 MB/s
536870912 Bytes (537 MB, 512 MiB) kopiert, 14,9089 s, 36,0 MB/s
536870912 Bytes (537 MB, 512 MiB) kopiert, 14,9048 s, 36,0 MB/s

RESULT (AVG):
============
Overlay config                      core_freq   turbo   overclock_50    WRITE        READ        HDPARM
                                      500        1      83.333 MHz     inf MB/s     inf MB/s   35.44 MB/s
[email protected]:/home/pi#
without overclock:

Code: Select all

[email protected]:/home/pi# sudo ./sdbench.sh
CONFIG:
CLOCK : 50.000 MHz
CORE  : 500 MHz, turbo=1
DATA  : 512 MB, /root/test.dat

HDPARM:
======
 Timing O_DIRECT disk reads:  66 MB in  3.02 seconds =  21.84 MB/sec
 Timing O_DIRECT disk reads:  66 MB in  3.04 seconds =  21.72 MB/sec
 Timing O_DIRECT disk reads:  66 MB in  3.04 seconds =  21.70 MB/sec

WRITE:
=====
536870912 Bytes (537 MB, 512 MiB) kopiert, 42,9755 s, 12,5 MB/s
536870912 Bytes (537 MB, 512 MiB) kopiert, 46,2965 s, 11,6 MB/s
536870912 Bytes (537 MB, 512 MiB) kopiert, 43,7983 s, 12,3 MB/s

READ:
====
536870912 Bytes (537 MB, 512 MiB) kopiert, 24,0375 s, 22,3 MB/s
536870912 Bytes (537 MB, 512 MiB) kopiert, 24,3466 s, 22,1 MB/s
536870912 Bytes (537 MB, 512 MiB) kopiert, 24,684 s, 21,7 MB/s

RESULT (AVG):
============
Overlay config                      core_freq   turbo   overclock_50    WRITE        READ        HDPARM
                                      500        1      50.000 MHz     inf MB/s     inf MB/s   21.76 MB/s
So my question is why ist the "CLOCK : 83.333 MHz" when I set it to 100MHz in config.txt?

Thank you!

EDIT:
Ok. Something steange just happened.
I pressed shift when RPi booted up to skip reading /boot/config.txt (??).
So I ran sdbench.sh again and output was

Code: Select all

CONFIG:
CLOCK : 100.000 MHz
CORE  : 500 MHz, turbo=1
DATA  : 512 MB, /root/test.dat

HDPARM:
======
 Timing O_DIRECT disk reads: 128 MB in  3.03 seconds =  42.29 MB/sec
read() failed: Input/output error
 Timing O_DIRECT disk reads:


WRITE:
=====
./sdbench.sh: line 21: rm: command not found

./sdbench.sh: line 21: rm: command not found

./sdbench.sh: line 21: rm: command not found


READ:
====
./sdbench.sh: line 21: /bin/sync: No such file or directory
./sdbench.sh: line 22: awk: command not found
./sdbench.sh: line 23: awk: command not found
./sdbench.sh: line 27: awk: command not found

./sdbench.sh: error reading input file: Input/output error
Bus error
[email protected]:/home/pi#
But then I could not do anything.
"shutdown now" was not a known command and SSH connection was unavailable.

I had to switch RPi off...

EDIT2:
Ok the shift-stuff had nothing to do with that.
I just normally rebooted the RPi and did a bench again with 100MHz and it again stopped at third write-test.
So I guess its just unstable and crashes.

I'll keep it at 83,3 MHz which is a good speed-boost compared to 50MHz.

Return to “Troubleshooting”