https://techcrunch.com/2018/01/11/intel-details-performance-hit-for-meltdown-fix-on-affected-processors/

Now that the Meltdown and Spectre cats are out of the bag and patches are being issued left and right, the main question people have is: will this affect my everyday work? Intel’s latest performance metrics suggest that yes it might, but not too much — more so if, like me, you have an older processor.

Intel’s Navin Shenoy released the results of several benchmarks done internally, and the performance hit from the deeply rooted processor problem disclosed by Google researchers is mercifully small for modern chips.