Original 45nm Intel® Core™ Microarchitecture

  Section 6 of 10  

Power Management Enhancements in the 45nm Intel® Core™ Microarchitecture

EDAT

Performance measurements on the latest Penryn family of processors mobile quad-core processors showed that Dual EDAT gave the expected performance gains on SPECInt2000, SPECFP2000, and their two-threaded SPEC rate counterparts. (Refer to “45nm Intel Core 2 Processor Silicon Performance” in this issue of the Intel Technology Journal, where Figures 11 and 12 show that Dual EDAT yielded a healthy 5 percent to 8 percent performance increase on these workloads for an 11 percent frequency boost over the guaranteed frequency [4] ). Note that Dual EDAT has an idle core limit of two or more; hence, running SPEC rate with three or more copies does not result in any performance improvement.

Like most of the power and performance features, we tuned the EDAT hysteresis mechanism post-silicon to give the best performance on processor-intensive benchmarks such as SPEC2000. (Figure 6) indicates that it recovered over half of lost performance gains due to high interrupt rates.

For EDAT hysteresis measurements, we used the Mobile Customer Reference board configuration with a Penryn 2.40 (HFM) 2.60(EDAT) GHz, an 800MHz Bus, and 2×2 GB FB DIMM at 667MHz. The operating system was Windows XP SP2*. The Workload was SPEC2000 measured by enabling and disabling the EDAT hysteresis mechanism with a timer interrupt rate at 1,000 interrupts second.

  Section 6 of 10  

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