http://www.techradar.com/news/intels-meltdown-and-spectre-patches-are-affecting-the-stability-of-some-pcs-with-older-cpus

Intel has cautioned that the fixes for the Meltdown and Spectre bugs may cause instability with some older processors, while the firm’s CEO also issued a statement promising greater transparency regarding these sort of major vulnerabilities going forward.

The bad news on the fix front applies to Broadwell and Haswell CPUs in terms of both consumer and data center use, with rebooting issues apparently plaguing some users.