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Surveying Virtualization Performance Trends with VMmark

The trends in published VMmark scores are an ideal illustration of the historical long-term performance gains for virtualized platforms. We began work on what
would become VMmark 1.0 almost five years ago. At the time, ESX 2.5 was the state-of-the-art hypervisor. Today’s standard features such as DRS, DPM, and Storage VMotion were in various prototype and development stages. Processors like the Intel Pentium4 5xx series (Prescott) or the single-core AMD 2yy-series Opterons were the high-end CPUs of choice. Second-generation hardware-assisted virtualization features such as AMD’s Rapid Virtualization Indexing (RVI) and Intel’s Extended Page Tables (EPT) were not yet available. Nevertheless, virtualization’s first wave was allowing customers to squeeze much more value from their existing resources via server consolidation. Exactly how much value was difficult to quantify. Our VMmark odyssey began with the overall goal of
creating a representative and reliable benchmark capable of providing meaningful comparisons between virtualization platforms.

VMmark 1.0 released nearly three years ago after two years of painstaking work and multiple beta releases of the benchmark. The reference architecture for VMmark 1.x is a two-processor Pentium4 (Prescott) server running ESX 3.0. That platform was capable of supporting one VMmark tile (six VMs) and by definition achieved a score of 1.0. (All VMmark results are normalized to this reference score.) The graph below shows a sampling of published two-socket VMmark scores for each successive processor generation. 

Blog_slide_3 ESX 3.0, a vastly more capable hypervisor than ESX 2.5, had arrived by the time of the VMmark 1.0 GA in mid-2007. Greatly improved CPU designs were also available. Two processors commonly in use by that time were the dual-core Xeon 51xx series and the quad-core Xeon 53xx series. ESX 3.5 was released with a number of performance improvements such as TCP Segmentation Offloading (TSO) support for networking in the same timeframe as the Xeon 54xx. Both ESX 4.0 and Intel 55xx (Nehalem) CPUs became available in early 2009. ESX 4.0 was a major new release with a broad array of performance enhancements and supported new hardware feature such as EPT and simultaneous multi-threading (SMT), providing a significant boost in overall performance. The recently released hexa-core Intel 56xx CPUs (Westmere) show excellent scaling compared to their quad-core 55xx brethren. (Overall, ESX delivers excellent scaling and takes advantage increased core-counts on all types of servers.) What is most striking to me in this data is the big picture: the performance of virtualized consolidation workloads as measured by VMmark 1.x has roughly doubled every year for the past five years.

In fact, the performance of virtualized platforms has increased to the point that the focus has shifted away from consolidating lightly-loaded virtual machines on a single server to virtualizing the entire range of workloads (heavy and light) across a dynamic multi-host datacenter. Not only application performance but also infrastructure responsiveness and robustness must be modeled to characterize modern virtualized environments. With this in mind, we are currently developing VMmark 2.0, a much more complex, multi-host successor to VMmark 1.x. We are rapidly approaching a limited beta release of this new benchmark, so stay tuned for more. But in this post, I’d like to look back and remember how far we’ve come with VMmark 1.x. Let’s hope the next five
years are as productive.