ROCK64: RAM overclock possible?

n30dg · November 18, 2017

Hello,

I was able to overclock the CPU to 1.488Ghz by editing rk3328-rock64.dtb file. But I can not figure out how to set the RAM-clock-speed.

Is there any chance to ramp up the RAM clock?

tkaiser · November 18, 2017

11 minutes ago, n30dg said:

I was able to overclock the CPU to 1.488Ghz by editing rk3328-rock64.dtb file

Care to report the instabilities you will now run into (before others find this thread and think this would be a great idea)?

You could start with https://github.com/ehoutsma/StabilityTester but would need to adjust both MAXFREQUENCY and the REGULATOR_* variables first.

n30dg · November 18, 2017

41 minutes ago, tkaiser said:

Care to report the instabilities you will now run into (before others find this thread and think this would be a great idea)?

You could start with https://github.com/ehoutsma/StabilityTester but would need to adjust both MAXFREQUENCY and the REGULATOR_* variables first.

I havn't discovered any instabilitie issues. The Board is running now (with these settings) for over 21days @ 100% load.

I'm running a self-compiled NEON-optimized Version of Einstein@home's GW-App(LowFreq).

Sure in order to get it stable at this high frequency, I had to ramp up the Voltage to 1.425V. Which is much above the recommended max. Voltage of 1.35V.

And I wouldn't recommend this (quiet dangerous) setting to any other user. Thats why I don't included a detailed discription in my post.

zador.blood.stained · November 18, 2017

53 minutes ago, n30dg said:

Is there any chance to ramp up the RAM clock?

Not now. Currently RK3328 uses closed source blobs for DRAM initialization, open-source SPL implementation was posted recently and it could be available in the future - probably in 3-6 months in mainline u-boot, not sure if Rockchip will backport those changes to their BSP u-boot.