Andrew Morton recently posted some interesting benchmarks comparing the current 2.4 IO scheduler, a "hacked" version of the deadline IO scheduler in 2.5.61, the CFQ scheduler, and the anticipatory scheduler. Offering a succinct "executive summary" of his results, Andrew said, "
the anticipatory scheduler is wiping the others off the map, and 2.4 is a disaster." Indeed, in many of the tests the other IO schedulers were measured in minutes, whereas the anticipatory IO scheduler was measured in mere seconds.
Read the report at KernelTrap by Jeremy Andrews.