Intel has published the results of the test conducted on the Meltdown and Spectre patches and their impact on performance confirms serious problems. The tech giant systems with several types of processors running Spectre patches may experience more frequent reboots. The tests are related to benchmarks that cover typical workloads for enterprise and cloud customers. The most severe degradation of the performance was observed during Storage Performance Development Kit (SPDK) tests, using iSCSI the degradation reached 25% when only a single core was used. Only the newest Intel 8th-gen CPUs Coffee Lake seems to be not affected by reboots.”]
Source: http://securityaffairs.co/wordpress/67905/security/meltdown-and-spectre-patches.html