SunSpider is quickly outlasting its welcome as a smartphone benchmark, but it does do a great job of highlighting issues with the Cortex A9's memory interface. Intel originally hinted at issues in the A9's memory interface as being why Atom was able to so easily outperform other ARM based SoCs in SunSpider. As we surmised in our A6 Geekbench post, it looks like Apple specifically targeted improvements in the memory subsystem when designing the A6's CPU cores. The result is the fastest SunSpider test we've ever recorded on a smartphone - faster even than Intel's Atom Z2460.
Take a look at the chart below...