http://vanshardware.com/2010/08/mirror-the-coming-war-arm-versus-x86/
Conclusion
The ARM Cortex-A8 achieves surprisingly competitive performance across many integer-based benchmarks while consuming power at levels far below the most energy miserly x86 CPU, the Intel Atom. In fact, the ARM Cortex-A8 matched or even beat the Intel Atom N450 across a significant number of our integer-based tests, especially when compensating for the Atom’s 25 percent clock speed advantage.
However, the ARM Cortex-A8 sample that we tested in the form of the Freescale i.MX515 lived in an ecosystem that was not competitive with the x86 rivals in this comparison. The video subsystem is very limited. Memory support is a very slow 32-bit, DDR2-200MHz.
Languishing across all of the JavaScript benchmarks, the ARM Cortex-A8 was only one-third to one-half as fast as the x86 competition. However, this might partially be a result of the very slow memory subsystem that burdened the ARM core.
More troubling is the unacceptably poor double-precision floating-point throughput of the ARM Cortex-A8. While floating-point performance isn’t important to all tasks and is certainly not as important as integer performance, it cannot be ignored if ARM wants its products to successfully migrate upwards into traditional x86-dominated market spaces.
However, new ARM-based products like the NVIDIA Tegra 2 address many of the performance deficiencies of the Freescale i.MX515. Incorporating two ARM Cortex-A9 cores (more specifically, two ARM Cortex-A9 MPCore processors), a vastly more powerful GPU and support for DDR2-667 (although still constrained to 32-bit access), the Tegra 2 will doubtlessly prove to be highly performance competitive with the Intel Atom, at least on integer-based tests. Regarding the Cortex-A8’s biggest weakness, ARM representatives told us its successor, the Cortex-A9, “has substantially improved floating-point performance.” NVIDIA’s CUDA will eventually also help boost floating-point processing speed on certain chores.
