Clock Drift in Linux

[zmc]

I'm running Debian 7 on the parallella and I'm having some extreme wall clock drift. I have a cronjob running every hour and I have seen the clock drift as much as 18 seconds. I'm using the machine as a desktop with huge loads all over, and 10 or so devices connected via usb, and swapping pretty much all day.

I had a similar issue on my SunBlade150 sparc64 machine, and I had to set the clock tic on boot. Has anyone else experienced a huge drift like this or have any idea how to start tracking it down?

[Gravis]