I've not ordered mine (yet!), but I do some overclocking as a hobby to the extent that my netbook, Android phone, desktop, and even my wife's Blackberry are overclocked.
Is there potential to overclock the RPi beyond stock voltage and speeds?
I figure I can rig some sort of custom cooling if need be.
Without overvoltage (i.e. at the default 1.2V), most Pis can run at up to 800MHz stably.
With overvoltage, 1000MHz is common.
WARNING: Setting any of the parameters which over volt your Raspberry Pi will set a permanent bit within the SOC and your warranty is void. So If you care about the warranty do not adjust voltage.
References:
The Raspberry Pi contains a /boot/config.txt.
This file is read by the GPU before the ARM core is initialised. It can be used to set various system configuration parameters. Which can be used for overclocking.
WARNING: Setting any of the following parameters which over volt your Raspberry Pi will set a permanent bit within the SOC and your warranty is void. So If you care about the warranty do not adjust voltage.
|:---------------------|------------------------------------------------------:|
| Option | |
|:---------------------|------------------------------------------------------:|
| arm_freq | frequency of ARM in MHz. Default 700.
| gpu_freq | Sets core_freq, h264_freq, isp_freq, v3d_freq
| | together.
| core_freq | frequency of GPU processor core in MHz. Default 250.
| h264_freq | frequency of hardware video block in MHz. Default 250.
| isp_freq | frequency of image sensor pipeline block in MHz.
| | Default is 250.
| v3d_freq | frequency of 3D block in MHz. Default 250.
| sdram_freq | frequency of SDRAM in MHz. Default 400.
| over_voltage | ARM/GPU core voltage adjust. [-16,8] equates to
| | [0.8V,1.4V] with 0.025V steps. Default 0 (1.2V) [1]
| over_voltage_sdram | Sets over_voltage_sdram_c, over_voltage_sdram_i,
| over_voltage_sdram_p together
| over_voltage_sdram_c | SDRAM controller voltage adjust. [-16,8] equates to
| | [0.8V,1.4V] with 0.025V steps. Default 0 (1.2V) [1]
| over_voltage_sdram_i | SDRAM I/O voltage adjust. [-16,8] equates to
| | [0.8V,1.4V] with 0.025V steps. Default 0 (1.2V)[1]
| over_voltage_sdram_p | SDRAM phy voltage adjust. [-16,8] equates to
| | [0.8V,1.4V] with 0.025V steps. Default 0 (1.2V)[1]
|:----------------------------------------------------------------------------:|
From the elinux wiki.
There are a list of confirmed clock speeds achieved which would save you some time: http://elinux.org/RPi_config.txt#Overclocking_options so someone has managed 1000MHz with some overvolting applied, of course this invalidates your warranty so maybe stock up on a few :)
I overclocked mine without touching the voltage for a long time:
arm_freq=940
gpu_freq=380
sdram_freq=530
overvoltage=0
I tested these values with quake and my rpi never crashed with this oc.
After trying it with voltage I got these values. They are "floored" because I didn't want to reboot everytime for every 10MHz.
arm_freq=1000
core_freq=500
sdram_freq=600
overvoltage=2
This might not run stable with quake3 but is rocksolid as Spigot (Minecraft) server.
It's a UK-built Model B from late 2013 (got it last christmas :D). Just to be more precise what hardware we are talking about.
I am currently using:
arm_freq=1100
sdram_freq=600
overvoltage=12
core_freq=500
The highest temperature my CPU has ever reached is 61 degrees. However the overclocking capabilities change depending on the manufacturer and batch.
