streamlining CPU performance
Software Controls Cache Memory to Speed CPUs
Letting the operating system control cache memory management saves power too
A new process for managing the fast-access memory inside a CPU has led to as much as a twofold speedup and to energy-use reductions of up to 72 percent. According to its designers, realizing such stunning gains requires a big shift in what part of the computer controls this crucial memory: Right now that control is hard-wired into the CPU’s circuitry, but the substantial speedup came when the designers let the operating system handle things instead.
The CPU uses high-speed internal memory caches as a kind of digital staging area. Caches are a CPU’s workbench, whether they’re holding onto instructions a CPU may need soon or data it may need to crunch. And from smartphones to servers, nearly every CPU today manages the flow of bits in and out of its caches using algorithms built into its own circuits.
But, say two MIT researchers, as computers and portable devices accumulate more and more memory and CPU cores, it makes less and less sense to leave cache management entirely up to the CPU. Instead, they say, it might be better to let the operating system share the burden.
Image courtesy AMD