In this paper, we empirically evaluate fundamental design trade-offs among the most recent multicore processors and accelerator technologies. Our primary aim is to aid application designers in better mapping their software to the most suitable architecture, with an additional goal of influencing future computing system design. We specifically examine five architectures, based on: the Intel quadcore Harpertown processor, the AMD quad-core Barcelona processor, the Sony-Toshiba-IBM Cell Broadband Engine processors (both the first-generation chip and the second-generation PowerXCell 8i), and the NVIDIA Tesla C1060 GPU. We illustrate the software implementation process on each platform for a set of widely-used kernels from computational statistics that are simple to reason about; measure and analyze the performance of each implementation; and discuss the impact of different architectural design choices on each implementation.