Overclocking

Warning: There is the possibility of damaging your equipment by overclocking. Do so at your own risk!

This page is incomplete, you're welcome to improve it.

All information regarding clock speeds, voltages and more are stored in the DTB (Device Tree Blob). You can learn more about it here.

Overclocking is a way to get more performance out of the system by running it at higher clock speeds than the factory default, usually while putting out more heat and using more power (You can also downclock to possibly reduce power consumption and thermals at the cost of performance). It is highly recommended that you avoid overvolting the device, as that has a high risk of damaging the hardware, hence the warning at the beginning of this page. However, just some slight overclocks without the added voltage can not only improve performance, but not carry as much risk (Still: Do at your own risk!). It should be noted however that overclocking can cause instability, so you will need to test and see what values work best with your device (There is a silicon lottery for the Pinephone's hardware).

A64-based devices

These instructions are targeting the Pinephone to simplify the explanation, however they can be used to also overclock other devices such as the Pinetab if you modify the proper DTB files.

Editing the Pinephone DTS

In order to overclock the Pinephone you will have to first convert the DTB file in /boot/dtbs/allwinner/ to a DTS file. You will see sun50i-a64-pinephone-1.2.dtb, and also two other files with different pinephone mainboard revisions (1.1 and 1.0). You will want to select the correct file for your pinephone (Only choose 1.1 if you have a braveheart, As all other consumer pinephones use the 1.2 DTS).

Once you've found the file, you can run the following command to convert the DTB to DTS: dtc -I dtb -O dts /boot/dtbs/allwinner/sun50i-a64-pinephone-1.2.dtb -o /boot/dtbs/allwinner/sun50i-a64-pinephone-1.2.dts

Finally, modify the newly converted .dts file and change the clockspeeds you wish to modify. You can simply use a text editor to do so.

To convert back to DTB: dtc -I dts -O dtb /boot/dtbs/allwinner/sun50i-a64-pinephone-1.2.dts -o /boot/dtbs/allwinner/sun50i-a64-pinephone-1.2.dtb

Afterwards you can simply reboot and check with sudo cat /sys/kernel/debug/clk/clk_summary to see if the changes have correctly applied.

In the future it is possible that someone may make a driver to adjust clockspeeds of the A64 from userspace (using a config file) without the need to recompile. However, currently the only way to overclock is to either compile your own kernel, or modify just the DTB (instructions above).

GPU

Open /boot/dtbs/allwinner/sun50i-a64-pinephone-1.2.dts (You will have to find the source of the kernel used by your distribution. There is the Pine64 kernel, and Megi's) in a text editor following these instructions: https://wiki.pine64.org/wiki/Overclocking#Edit_Pinephone_DTS

Look for mali: gpu@1c4000 { and within that block search for assigned-clock-rates = <432000000>;

The assigned-clock-rates line should be set to 432000000, this means that the GPU is clocked at 432MHz by default. So if you want 500MHz, set the value to 500000000.

Save the dts file, and recompile the DTB. In order to check if the overclock was successfully applied you can run: sudo cat /sys/kernel/debug/clk/clk_summary.

The file may be slightly different and you may need to enter the values as hexidecimals

The GPU appears to run stable overclocked to 560 Mhz, however more testing with a wider group of devices is needed.

Remember to run a benchmark tool (such as glmark2-es2) to help check stability.

CPU

The stock speed of the A64 is 1.152 GHz. It is not recommended to the overclock the CPU because doing so greatly increases power and thermals and will overheat the device for little to no gain.

DRAM

Warning: It is not recommended to exceed 667 MHz clockspeed on the DRAM. 624MHz is likely the upper limit.

Make sure to set your DRAM to a multiple of 24.

When overclocking the GPU, it is a good idea to also overclock the DRAM, as the main bottleneck of the A64 SOC is the memory. The A64's maximum ram clockspeed falls just short of 667MHz. This may be unstable on your device however.

Around 600 MHz (PC-1200) should work fine, however some people have reported instability at lower clockspeeds. Arch Linux Arm uses a default clockspeed of 552MHz, with uboot builds available to easily switch out for a higher (624) or lower (492) DRAM clockspeed.

It is possible that by reverse engineering the DRAM driver from allwinner that auto tuning can be accomplished to get the best performance.

Setting the DRAM clock is accomplished by modifying pinephone_defconfig in uboot (https://gitlab.com/pine64-org/u-boot/-/blob/crust/configs/pinephone_defconfig)

You can find simple instructions on doing so here: Uboot

VPU

In order to allocate more VRAM for the GPU you can add cma=256 to your kernel (or use kconfig with CONFIG_CMA_SIZE_MBYTES=256) cmdline in boot.scr which you will have to compile using mkimage. By default the kernel allocates only 64MB, and the maximum value is 256MB.

In order to compile boot.scr you can run mkimage -C none -A arm64 -T script -d boot.cmd boot.scr

You may not have a boot.cmd file in your boot directory and instead you may instead have a boot.txt

Cedrus

Overclocking cedrus is achieved by modifying the kernel source code: https://elixir.bootlin.com/linux/latest/source/drivers/staging/media/sunxi/cedrus/cedrus.c#L507

I'm (33yn2) not particularly sure if this makes any difference, or if it might infact have a negative impact. Probably not worth messing with.

RK3399-based devices

The RK3399 clocks are found in arch/arm64/boot/dts/rockchip/rk3399-opp.dtsi

More optimised voltages and clocks can be found in arch/arm64/boot/dts/rockchip/rk3399-op1-opp.dtsi These include a slight overclock and undervolt, they are intended for the OP1 CPU found in many chromebooks but have worked fine in all recorded cases on regular RK3399s in other devices.

GPU

Any clock speeds can be added for the GPU in gpu_opp_table

The highest safe voltage for the GPU is 1.2V as specified in the RK3399 schematic from Rockchip.

Segfault has found that the RK3399 in his Pinebook Pro can reach 950MHz on the GPU while being stable.

The stock speed for the GPU is 800Mhz.

CPU

A set of available clock speeds that can be added to the CPU clusters can be found in drivers/clk/rockchip/clk-rk3399.c under rk3399_cpuclkl_rates for the little cores and rk3399_cpuclkb_rates for the big cores.

These clock speeds can be added to cluster0_opp for the small cores and cluster1_opp for the big cores respectively.

There is a hard limit of 1.8GHz on the little cores and 2.2GHz on the big cores.

The highest safe voltage for the little cores is 1.2V and for the big cores is 1.25V.

Segfault has found that the RK3399 in his Pinebook Pro can reach 1.6GHz on the little cores and 2.08GHz on the big ones.

The stock speed for the little cores is 1.4GHz and on the big cores it is 1.8GHz, however the OP1 speeds default to 1.5GHz and 2.0GHz instead.

ROCK64

DTB is in /boot/dtbs/rockchip/rk3328-rock64.dtb. CPU clock rates are inside opp_table0 as hexadecimal numbers in the opp-hz field.

Check the achieved clock speed with sudo cat /sys/kernel/debug/clk/clk_summary | grep armclk. Does not seem to overclock at stock voltages at all, defaults to 408 MHz if it fails to set a clock rate. Stock voltage is 1.30V, just shy of the 1.35V maximum outlined in the datasheet. Overvolting to 1.325V just left the device in an unbootable state for CounterPillow, would not recommend.

GPU needs investigating, but is seemingly tied to the bus speed.