Compiling a vanilla kernel on x86 hardware is one thing, building an ARM kernel is quite another in terms of performance, or at least that's been my experience.

Compiling a vanilla kernel on x86 hardware is one thing, building an ARM kernel is quite another in terms of performance, or at least that's been my experience. To give you an idea of how bad the difference is, to compile the Linux kernel in defconfig, using 2 distcc boxes each with AMD FX8320 3.5ghz (8 core) + 32gb ram + 1gb LAN. The x86 stuff boot off RAID1+0, the the PI obviously off its sdcard, here's what happens: * Compile for armv6 on pi host + distcc compile farm: 19 min 11 sec * Compile for armv6 on qemu host + distcc compile farm: 29 min 36 sec * Compile for armv6 on x86_64 hardware + cross toolchain + distcc compile farm: 1 min 59 sec * Compile for x86_64 defconfig on off-the-shelf x86_64 hardware (also fx8320) + distcc compile farm: 1 min 31 sec That's compiling "linux-3.6.9999-raspberrypi.tar.bz2" with -j20 across the board. I realise there's a number of problems with this "test" - obviously the last two are unfair, the PIs laughable shared bandwidth across network & usb gimp it horribly. I have no idea why qemu is so bad though, I pointed it at an img taken from a running PI vOv and I've probably done a million other things wrong getting the numbers. But to anyone intending to compile armv6 crap on a pi or qemu based compile farm: unless it's a one off thing or your time is worthless, don't do it. Invest the time getting crossdev, crosstool-ng etc + dist cc working properly. I only bothered because I was looking for a better way to build stuff for Android and used the setup as a testbed.