[jcalvinowens]

If you use the GPIO-based PPS on RT Linux, the kernel will soon get a nice improvement in jitter: https://lore.kernel.org/all/A0383FF7-267A-4D4C-9B74-F80B9908...

I've been testing it and it is noticeably better, but I haven't yet had time to set up an A/B test to get real numbers.