X220, How Does the Meltdown patch affect it.

Short answer it depends on what your doing

Check if its patched: sudo dmesg -wH | grep 'page tables isolation'

Umm benchmark links desu: http://www.mmxchan.org/files/benchmark/pti_off http://www.mmxchan.org/files/benchmark/pti_on http://www.mmxchan.org/tpg/res/52.html#52 ... https://www.youtube.com/watch?v=ei6R1Xjpz7U