Meltdown patch impact on data processing speeds
It looks like the Tech Web Sites that reported Meltdown, may have overblown the negative impacts.

According to Google, in their cloud infrastructure, there seems to be little to worry about:


  There has been speculation that the deployment of KPTI causes significant performance slowdowns. Performance can vary, as the impact of the KPTI mitigations depends on the rate of system calls made by an application. On most of our workloads, including our cloud infrastructure, we see negligible impact on performance.


Techspot  ran some benchmarks on Windows 10, and they concluded...


  Desktop users have little to worry about in terms of performance loss, particularly gamers. We've yet to test older CPUs, but given the type of workloads we’re seeing impacted by the patch, I don’t think there’s going to be an issue with any desktop hardware, but we’ll certainly report back if there is.