Raspberry Pi 3 Overclocking and Stability Testing

I recently ordered and took delivery of the new Raspberry Pi 3, with the intention of letting my son use it as a desktop computer replacement.

Web browsing with Chromium works pretty well, but was still a little bit laggy on Javascript-heavy sites, and I had hoped to eek a bit more performance out of it.

Inspired by this guy, I tried upping the clock speed, but needed a way to stress test it, and at the same time, check for stability. On x86 equipment, I would use Prime95 to fill that role: it has the CPU perform calculations, and compares the results with a known reference. If they don’t match, then the CPU has made an error (due to heat, voltage, a flipped bit somewhere in RAM or cache, etc).

Existing stress test software that I’ve encountered for the Raspberry Pi doesn’t seem to care about the integrity of the calculations performed. And since Prime95 doesn’t run on ARM processors, I came up with my own solution: a quick and dirty BASH script that will run four simultaneous iterations of a command that calculates a million digits of pi. It them makes sure the results match, outputs the time it took to execute the commands, and the temperature of the CPU core, and loops until it’s aborted with CTL-C, or it encounters an error.

Here’s that script:

My results were pretty disappointing, by the way. The stock clocking of the CPU, 1.2GHz, appears to be the highest speed this chip is able to handle stably.

Raspberry Pi with USB DAC running XBMC on OpenELEC

This is just a note to self, to make things easier when updating to a new build in the future. What I needed to do to get my Pi running correctly with Milhouse build 503:

First mount flash partition read/write:
mount -o rw,remount /flash

In /flash/config.txt:
gpu_mem=192
arm_freq=900
core_freq=333
sdram_freq=450
over_voltage=2
force_turbo=1

In /flash/cmdline.txt, add noram.

In Settings, System, enable advanced, then select ALSA USB DAC audio, enable passthrough, and DTS capable receiver.

In ~/.xbmc/userdata/advancedsettings.xml:

<advancedsettings>
<video>
<defaultdvdplayer>dvdplayer</defaultdvdplayer>
<defaultplayer>dvdplayer</defaultplayer>
</video>
<network>
<buffermode>1</buffermode>
</network>
</advancedsettings>

Ubuntu ZFS DKMS

In case I ever have issues again with ZFS DKMS:

https://github.com/zfsonlinux/zfs/issues/1155#issuecomment-11499841

Honda parts shipped to an APO address

I didn’t expect it to be so difficult to find an online Honda dealer that was willing to ship to an APO address. After wasting time on site after site after site, I finally found one that ships to APO, but wanted to charge over 4x their normal shipping rate! After further searching, I finally found a place that will ship Honda parts to military members overseas at APO address without price gouging them! Visit http://www.bkhondaparts.com if you need to order Honda parts for an APO address without getting ripped off. (or perhaps lingshondaparts.com ?)
(this is mainly a note to myself)