https://www.theregister.co.uk/2018/01/10/intel_allows_that_meltdown_and_spectre_may_slow_servers_down/

After spending last week insisting that the performance impact of fixing the Meltdown and Spectre CPU vulnerabilities "should not be significant," Intel on Tuesday tried to maintain that stance even as it acknowledged SYSmark tests assessing post-patch slowdowns ranging from two per cent to 14 per cent.

Reiterating that typical consumer and business usage – reading email, opening documents, and accessing digital photos – should not exhibit any performance hit from remediation, Intel said, "8th Generation Core platforms with solid state storage will see a performance impact of six per cent or less."