10GbE pipes on the Romley (officially the Intel Xeon Processor E5-2600, previously known as Sandy Bridge) server motherboard are a “good thing”; simple queuing theory tells you that the throughput for a given response time will be much higher from a single 10GbE pipe compared with ten 1GbE pipes. Fewer ports means less real-estate, less power, and fewer switches. And of course, many fewer cables. Slam dunk, right?
Clearly applications that are bandwidth-constrained (e.g., some big data applications and some high performance compute (HPC) applications) should move to the Romley-based servers in a heart-beat. The combination delivers blazing processor performance and bandwidth. But the simple fact is that there are not many applications that consume 10GbE’s worth of bandwidth. This is especially true in virtualized environments, where a 10GbE pipe must be shared across multiple processors, cores, operating systems, and applications.
Broadcom, QLogic, and other 10gE providers have the ability to carve out logical partitions within a 10GbE pipe and provide shared IO with multiple connections and multiple protocols. Blade systems have already provided a different solution to IO sharing. For example, the HP blade systems have been using Virtual Connect to virtualize the IO for years. The result is far fewer cables and higher speed connections coming out of the blade system. There is clearly a need for IO sharing in virtualized non-blade systems, with large numbers of small virtual systems on a single physical machine.
What is also equally clear is that the supporting software ecosystem is not yet in place for rack-based and tower servers. The focus area for the ecosystem surrounding Romley and 10GbE needs to be the optimization of operating systems, hypervisors, and key middleware to be able to exploit IO sharing efficiently. For example, a single processor has a individual L1 cache to manage; in multi-core implementations each core shares that cache. The IO systems in hypervisors and operating systems will need significant improvement to avoid trashing the shared cache. Management, problem determination and security will also need to be significantly enhanced.
Action Item: CXOs and server specialists should demand that vendors package and brand Romley servers together with the correct OS, hypervisor, and middleware software technologies to deliver proven improvements in throughput with minimal retraining of staff and changes in management and security procedures. VMware, Hyper-V are Xen should be the initial targets for these configurations.
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