2.2. Performance
2.2. Performance Older virtualization versions supported only a single CPU. As a result, virtual machines experienced noticeable performance limitations. This created a long-lasting misconception that virtualization solutions are slow. This is no longer the case. Modern virtualization technology has greatly improved the speed of virtual machines. Benchmarks show that virtual machines can run typical server applications nearly as efficiently as bare-metal systems: Red Hat Enterprise Linux 6.4 and KVM recorded an industry-leading TPC-C benchmark with an IBM DB2 database running in an entirely virtualized x86 environment and delivering 88% of bare-metal performance. Due to resource demands, databases have previously been reserved for bare-metal deployments only. The industry standard SAP Sales and Distribution (SD) Standard Application Benchmark found that Red Hat Enterprise Linux 6.2 and KVM performs at the virtualization efficiency of 85% compared to a bare-metal system running on identical hardware. Red Hat Enterprise Linux 6.1 and KVM achieved record-setting virtualization performance in the SPECvirt_sc2010 benchmark recorded by the Standard Performance Evaluation Corporation (SPEC), setting the best virtual performance mark of any published SPECvirt result. The SPECvirt_sc2010 metric measures the end-to-end performance of system components in virtualized data center servers. Note For more information on performance tuning for virtualization, refer to the Red Hat Enterprise Linux 6 Virtualization Tuning and Optimization Guide .