SAN JOSE: GRAY BOX MAKER Dell claims that chips with turbo boost features such as Intel Xeon processors are causing lower performance for workloads that require synchronisation between threads that run on different cores.
Intel has been growing increasingly reliant on processors that have nominal base frequencies that turbo boost to higher frequencies, which the firm and its rivals claim provide performance on demand. However Dell said that in certain workloads users are complaining that the different clock speeds and the time taken to ramp up clock speeds are actually resulting in thread synchronisation problems that have a negative impact on overall performance.
Dell claims that this problem is particularly common in latency sensitive computing. Dell VP of Server Solutions Forrest Norrod cited high frequency stock trading as one example. Norrod called this problem jitter and said, "The jitter of the results [returned] meant that it was difficult to synchronise their systems together. The fact that turbo existed actually slowed down their results."
Norrod then said that Dell's own thread synchronisation software, which runs on both Microsoft Windows and Linux, not only improved performance but offered better energy efficiency than leaving the processor, an Intel Xeon E5-2690, set at a particular clock frequency. He said the software "improves application efficiency and saves significant power versus keeping all cores up to frequency whether they are busy or not".
Intel's core frequency ramping technology is not instant and, to be fair to Intel, it is not something that the firm has ever claimed, but that certain workloads are susceptible to both the latency and different frequencies of turbo boost is concerning as more and more workloads are spread over a greater number of cores.
Although Dell and its customers' problems are performance related and do not affect computing integrity, it is embarrassing for Intel that a system vendor such as Dell has to overlay software in order to overcome problems that should have been solved at the silicon level. µ
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