Raspberry Pi Forums

Posted: **Mon Sep 17, 2012 10:37 am**

how can I see that it is using the overclock when it needs to ?
i.e. I assume that cat /proc/cpuinfo will not show the new value

Posted: **Mon Sep 17, 2012 11:26 am**

For current frequency (in kHz)

Code: Select all

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
700000

Or enable the cpufreq addon to the lxde system tray, and hover over it.

Posted: **Mon Sep 17, 2012 11:49 am**

+1 excellent
all happy now

Posted: **Mon Sep 17, 2012 5:11 pm**

dom wrote:The tempertaure sensor is now available through a thermal driver.

Excellent, thanks for all this. Temp showing fine in gkrellm. Now need to write a plugin to show the clock speeds and voltages - recommend nobody holds their breathe as it is a couple of decades since my previous line of code!

Posted: **Wed Sep 19, 2012 1:10 pm**

Check out the blog post:
http://www.raspberrypi.org/archives/2008

and you'll understand the tweaks to overclocking behaviour that have been occurring over the last couple of weeks.

Note, that overclocking through raspi-config doesn't set your "warranty" bit. What sets the warranty bit now, is:

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(force_turbo || current_limit_override || temp_limit>85) && over_voltage>0

So, if you are manually overclocking and want to know what is "allowed", then stick to those config.txt options.
If you've already blown your warranty bit, or don't care, then feel free to change anything.

Posted: **Wed Sep 19, 2012 3:12 pm**

did something changed in the latest cpufreq driver, becose my arm is always at 700mhz no matter what.
Worked fine before i updated the image...

forced turbo works though..

Posted: **Wed Sep 19, 2012 3:15 pm**

hojnikb wrote:did something changed in the latest cpufreq driver, becose my arm is always at 700mhz no matter what.
Worked fine before i updated the image...
forced turbo works though..

Yes, we boot up with powersave governor and switch to ondemand with init script. "apt-get upgrade" should get you this bevaviour, but you can do it manually by adding:
echo “ondemand” > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
to /etc/rc.local.

Posted: **Wed Sep 19, 2012 3:24 pm**

Oh thanks for clearing that up. Never though powersave governour is so agressive

is there any good reason for using powersave gov. out of the box ?

Posted: **Wed Sep 19, 2012 3:26 pm**

hojnikb wrote:Oh thanks for clearing that up. Never though powersave governour is so agressive
is there any good reason for using powersave gov. out of the box ?

By booting with powersave and then enabling ondemand in init script, we can implement the "hold shift" to disable overclock, so you can recover from a "too high" overclock that won't boot.

Posted: **Wed Sep 19, 2012 3:27 pm**

dom wrote:
hojnikb wrote:did something changed in the latest cpufreq driver, becose my arm is always at 700mhz no matter what.
Worked fine before i updated the image...
forced turbo works though..
Yes, we boot up with powersave governor and switch to ondemand with init script. "apt-get upgrade" should get you this bevaviour, but you can do it manually by adding:
echo “ondemand” > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
to /etc/rc.local.

The init script to switch governor is generated once you use raspi-config to set one of the overclock presets.

Posted: **Wed Sep 19, 2012 3:33 pm**

dom wrote:
hojnikb wrote:Oh thanks for clearing that up. Never though powersave governour is so agressive
is there any good reason for using powersave gov. out of the box ?
By booting with powersave and then enabling ondemand in init script, we can implement the "hold shift" to disable overclock, so you can recover from a "too high" overclock that won't boot.

I see..
That makes sense

Posted: **Wed Sep 19, 2012 3:54 pm**

How can you check the warranty bit ? I searched the forums but couldn't find a way.

I unfortunatly discovered force_turbo just last night and can't remember if i had it enabled when i switched SD cards into another Pi, tis a bummer if that's tripped the warranty bit as i wasn't overvolting, i thought that as the only way to void the warranty, doh!

Posted: **Wed Sep 19, 2012 3:59 pm**

chickey wrote:How can you check the warranty bit ? I searched the forums but couldn't find a way.
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cat /proc/cpuinfo  |grep Revision
Revision        : 1000004
The 1 at the start (bit 24) is the warranty bit.
chickey wrote:I unfortunatly discovered force_turbo just last night and can't remember if i had it enabled when i switched SD cards into another Pi, tis a bummer if that's tripped the warranty bit as i wasn't overvolting, i thought that as the only way to void the warranty, doh!

You may be okay. force_turbo doesn't set it on its own. Only in conjunction with over_voltage>0.

Posted: **Wed Sep 19, 2012 5:30 pm**

asb wrote:
dom wrote:
hojnikb wrote:did something changed in the latest cpufreq driver, becose my arm is always at 700mhz no matter what.
Worked fine before i updated the image...
forced turbo works though..
Yes, we boot up with powersave governor and switch to ondemand with init script. "apt-get upgrade" should get you this bevaviour, but you can do it manually by adding:
echo “ondemand” > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
to /etc/rc.local.
The init script to switch governor is generated once you use raspi-config to set one of the overclock presets.

I noticed that overclock doesnt work for me too.

I added the ondemand thing to /etc/rc.local , even tried the raspi-config to set one preset. The scaling_cur_freq still shows 700000. Do I have to do something else to enable the overclock?

Posted: **Wed Sep 19, 2012 5:37 pm**

Yoda007 wrote:I added the ondemand thing to /etc/rc.local , even tried the raspi-config to set one preset. The scaling_cur_freq still shows 700000. Do I have to do something else to enable the overclock?

Are you busy?

Try:

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for i in {1..10000} ; do set X 1; done && cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq

Posted: **Wed Sep 19, 2012 5:58 pm**

for i in {1..10000} ; do set X 1; done && cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
800000

I was using this command before to check:
cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
700000

my arm_freq=800.

Hm so it shows the real result if the CPU is working on something while I run the command

.

Didn't think of that

. So it saves power if not under load by staying at 700 and it goes to whatever you have set in the config.txt when there is stuff for the CPU to do. Nice.

Posted: **Wed Sep 19, 2012 7:14 pm**

Interesting ... I can run my pi at 1 MHz now ...

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# echo "powersave" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
# echo 1000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
# cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
1000
# time free
             total       used       free     shared    buffers     cached
Mem:        189104      80140     108964          0      10464      44276
-/+ buffers/cache:      25400     163704
Swap:            0          0          0

real    0m6.607s
user    0m1.400s
sys     0m3.310s

I wouldn't go much lower, though.

Where can I see the current gpu core freq and sdram freq? Can min/max values also be changed on the fly as is the case with the arm cpu frequency?

Posted: **Thu Sep 20, 2012 3:30 am**

What's the default ram value in MHz? forgive me for not back reading the thread.

I know the ARM mhz is 700mhz.. hehehe

Posted: **Thu Sep 20, 2012 3:32 am**

rilski wrote:What's the default ram value in MHz? forgive me for not back reading the thread.

I know the ARM mhz is 700mhz.. hehehe

250.

All defaults here.

Posted: **Thu Sep 20, 2012 3:57 am**

^
Thanks milhouse!

Posted: **Thu Sep 20, 2012 6:58 am**

Dom, it seems that overvolting and using the performance governor doesn't void the warranty. You might want to address this problem.

Also the new turbo mode (1000MHz ARM, 500MHz core, 500MHz SDRAM, 6 overvolt) is unstable for my particular Pi. My stress test method is running, dd if=/dev/zero | ssh 192.168.80.5 "dd of=/dev/null", stress --cpu 8 --vm 8 --vm-bytes 20M, and watch -n 1 vcgencmd measure_temp in different screen sessions.

I can do 900MHz ARM, 450 MHz core, 450 MHz SDRAM without overvolting very stably. I switch to performance governor after booting up. I can't use force_turbo, because apparently when my Pi is cold, I can't boot it up with my settings. However the problem disappears when the Pi is warm (around 55-60C). I guess only the God knows why this is the case...

Posted: **Thu Sep 20, 2012 7:46 am**

dom wrote:
hojnikb wrote:did something changed in the latest cpufreq driver, becose my arm is always at 700mhz no matter what.
Worked fine before i updated the image...
forced turbo works though..
Yes, we boot up with powersave governor and switch to ondemand with init script. "apt-get upgrade" should get you this bevaviour, but you can do it manually by adding:
echo “ondemand” > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
to /etc/rc.local.

I don't have anything in the cpu0 dir "apt-get upgrade" didn't work have ran all the update and upgrades can overclock but can't get cpu frequency the widget shows 0 any help how to get this

Posted: **Thu Sep 20, 2012 8:48 am**

When im looking at default OC settings, i see that core clock is really high (500 compared to 250)
Does core really overclocks that well ?
i never even tried more than 350..
Does core speed affects anything else than ARM L2 cache ?

Posted: **Thu Sep 20, 2012 10:13 am**

In case anyone else has this issue...

I was hitting a problem where the file " /sys/class/thermal/thermal_zone0/temp" existed however had a no size or content. Subsequently if you tried to cat the file, cat would simply hang.

It would seem you need to power off (physically) rather than just do a reboot after you update the firmware on the Pi.

Nevertheless it's all working now and I'm running in turbo mode (1Ghz). Not seen a temperature above 60 degrees C yet

Posted: **Thu Sep 20, 2012 10:40 am**

milhouse wrote:
rilski wrote:What's the default ram value in MHz? forgive me for not back reading the thread.
250.
All defaults here.

SDRAM is 400...

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