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Overclocking 1ghz

Posted: Sun Apr 20, 2014 9:16 am
by geoffpalmeruk

Re: Overclocking 1ghz

Posted: Sun Apr 20, 2014 9:43 am
by GTR2Fan
Guilty.

Re: Overclocking 1ghz

Posted: Sun Apr 20, 2014 10:01 am
by geoffpalmeruk
have you tried clocking higher than 1?

can you provide a shot like mine?

Re: Overclocking 1ghz

Posted: Sun Apr 20, 2014 10:23 am
by GTR2Fan
I can boot up at 1.1GHz, but it's not stable enough to do any serious work at that speed without raising the ARM voltage past the recommended safe limit. The best stress test I've found so far is the Darkplaces Quake engine. If your Pi can run that for 1 hour+ then it's probably completely stable. If you're interested in trying it, type 'Darkplaces' into the search box above.

I'm running various OSes via a modified NOOBS multi-boot front-end at the moment, so it's a little tricky showing the contents of 'config.txt' in a terminal on a remote PC as it's not present on the '/boot' partiton AFAICT, but these are the settings I use for my Raspbian OS configured for gaming...

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# Dynamic Overclocking & Overvolting
arm_freq=1000
core_freq=500
sdram_freq=500
over_voltage=6
force_turbo=0

# Disable Display Overscan
disable_overscan=1
By the way, your 'temp_limit=85' line is redundant as that's the default setting when not specified.

Re: Overclocking 1ghz

Posted: Sun Apr 20, 2014 1:13 pm
by geoffpalmeruk
Ah ok, so should i open up the config and delete it? I'm tempted to try going for 500mhz too. Is there any way to have it clock back if it fails to boot?

Re: Overclocking 1ghz

Posted: Sun Apr 20, 2014 6:49 pm
by GTR2Fan
geoffpalmeruk wrote:Ah ok, so should i open up the config and delete it?
I've just realised that I'm being an idiot because I mistook your 'vcgencmd get_config int' results for being the contents of a 'config.txt' file, so 'temp_limit=85' will appear in there even if you haven't manually set it. D'oh! :P
I'm tempted to try going for 500mhz too.
You already have for 'core_freq' according to your attached image.
Is there any way to have it clock back if it fails to boot?
Holding down the shift key on your keyboard when booting up Raspbian should defeat any custom overclocking settings, but I've never needed to use it so can't guarantee that it will if you're using user-defined custom settings.

Re: Overclocking 1ghz

Posted: Sun Apr 20, 2014 7:10 pm
by geoffpalmeruk
ah, i think i was having a bit of a stupid moment! lol. yeah i have it clocked to 600 and is showing as stable... well at least for general use as raspbmc media centre :)

Re: Overclocking 1ghz

Posted: Tue Apr 22, 2014 10:40 am
by geoffpalmeruk
Is there anyone else that has 1ghz or more? can't be just us!?

Re: Overclocking 1ghz

Posted: Tue Apr 22, 2014 10:43 am
by jamesh
geoffpalmeruk wrote:Is there anyone else that has 1ghz or more? can't be just us!?
Many many people. I tend to run 900, but most of the time I'm not bothered. I think Dom runs are 1Ghz all the time.

Re: Overclocking 1ghz

Posted: Tue Apr 22, 2014 10:53 am
by shuckle
Yes, 1 GHz is not that strange. This is my fastest machine:

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 $ vcgencmd get_config int
arm_freq=1100
core_freq=250
sdram_freq=500
over_voltage=6
disable_overscan=1
program_serial_random=1
temp_limit=85
force_pwm_open=1
$ uptime
 13:49:39 up 41 days,  5:02,  1 user,  load average: 2.29, 2.03, 1.86
I only overclock as needed.
This machine shows two security camera streams and also displays home automation data and weather forecast to a screen and works 24/7.

Re: Overclocking 1ghz

Posted: Tue Apr 22, 2014 11:24 am
by geoffpalmeruk
Not bad. That a 1.1 clock?

how are the temps and what case are you using?

Another random question the vcgencmd get_config int will show the clock speed etc but to get uptime you just need to type uptime?

Re: Overclocking 1ghz

Posted: Tue Apr 22, 2014 12:08 pm
by shuckle
geoffpalmeruk wrote:Not bad. That a 1.1 clock?

how are the temps and what case are you using?

Another random question the vcgencmd get_config int will show the clock speed etc but to get uptime you just need to type uptime?
Yes, it is 1,1 GHz and runs around 60 degrees Celcius.

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$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
1100000
$ cat /sys/class/thermal/thermal_zone0/temp
57838
It is in normal room temperature and in basic element14 see through plastic box attached to the wall.
And yes, uptime shows how long it has been running from latest boot.


My camera Raspi is running also as 1G, but it is still in test phase and only running mjpg_streamer (and the camera):

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$ vcgencmd get_config int
arm_freq=1000
over_voltage=6
program_serial_random=1
config_hdmi_boost=2
emmc_pll_core=1
temp_limit=85
force_pwm_open=1
pause_burst_frames=1
disable_camera_led=1
avoid_fix_ts=1
$ uptime
 15:05:48 up 6 days,  6:24,  1 user,  load average: 0.52, 0.51, 0.50
$ cat /sys/class/thermal/thermal_zone0/temp
44388
That one is still without a box and is running cooler around 45 C.

Re: Overclocking 1ghz

Posted: Tue Apr 22, 2014 12:17 pm
by geoffpalmeruk
sounds good :) i think i'll try it when i get my pi moved into my shortcrust case :)

Re: Overclocking 1ghz

Posted: Tue Apr 22, 2014 12:28 pm
by GTR2Fan
You'll nearly always get away with higher overclocks if temperatures are lower. Going on past experiments, I suspect that shuckle's Pi is probably happy at 1.1GHz because he's not overclocking the GPU which can add ~20°C if the GPU is being stressed heavily at 500MHz instead of 250. He's hitting 60°C versus my 80°C+ with the settings in my forum sig.

Don't be surprised if it becomes unstable at 1.1GHz with everything else maxxed out, especially if you don't have a heatsink or run the Pi in a confined space. As always, YMMV.

Re: Overclocking 1ghz

Posted: Tue Apr 22, 2014 12:36 pm
by geoffpalmeruk
Fair enough, I'm tempted to keep the 1ghz clock and try to boost the gpu freq to 260. see how that goes.

not needed as it all runs very nice and smoothly but just curious how high i can go before i break something!

Re: Overclocking 1ghz

Posted: Tue Apr 22, 2014 12:54 pm
by GTR2Fan
geoffpalmeruk wrote:...just curious how high i can go before i break something!
As long as you don't exceed the parameters of a foundation 'Turbo' overclock, you won't break anything and your warranty remains intact.

Overclocking the GPU on it's own with 'gpu_freq' won't do anything unless you modify another setting that potentially breaks warranty conditions and may set a permanent bit as a tell-tale marker that you've done so. The highest recommended settings that don't break warranty conditions are...

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arm_freq=1000
core_freq=500
over_voltage=6
sdram_freq=600
force_turbo=0
My RAM crashes when heavily stressed at 600MHz, so I went for 500 instead as I wanted total stability at all times.

All the settings information you need is here. :)

Re: Overclocking 1ghz

Posted: Tue Apr 22, 2014 1:07 pm
by geoffpalmeruk
So with the following:

arm_freq=1000
gpu_freq=258
core_freq=500
sdram_freq=600
over_voltage=6

I shouldn't blow my pi. In fact if i understand correctly it's running less than the foundations 'turbo' overclock?

Re: Overclocking 1ghz

Posted: Tue Apr 22, 2014 1:17 pm
by GTR2Fan
If I understand correctly how the settings interact, 'gpu_freq=258' is doing nothing so you might as well remove it. I don't know what 'force_turbo' defaults to, but bunging 'force_turbo=0' in there with the other settings you have guarantees you're foundation-approved safe. Anything else is entirely at your own risk.

Re: Overclocking 1ghz

Posted: Tue Apr 22, 2014 1:25 pm
by geoffpalmeruk
In fairness i have to come clean, i didn't clock in the config.txt file i did it all through raspbmc.

Re: Overclocking 1ghz

Posted: Tue Apr 22, 2014 1:54 pm
by gkreidl
I'm running with ARM 1GHz, RAM 500, and GPU 400 (that includes Core, H264 etc). For quite some time, I've been using 500 for the GPU, but got some rare irq errors in dmesg.

Stress test:
running OpenGL1Pi.bin in one half of the 1080p screen, and a 720p HD video with omyplayer in the other half (in a window, not fullscreen). Processor activity is around 85 - 90%. Both the GPU and the H264 unit are really busy this way.
Max temperature I get is about 66 C.

I've left the top of my case open after noticing last summer that the temperature got much higher, when it's closed. Air circulation in these RPi cases is rather bad.

Re: Overclocking 1ghz

Posted: Tue Apr 22, 2014 1:56 pm
by geoffpalmeruk
so can anyone advise of a config.txt file i can copy to test on my pi?
Full settings would be appreciated :)