From: Eric Wong Date: 2014-01-03T22:53:39+00:00 Subject: [ruby-core:59539] Re: [ruby-trunk - Feature #9362][Assigned] Minimize cache misshit to gain optimal speed Cool. I didn't expect the improvement for largely single-threaded workloads. I'm not sure if it's feasible, but it might be better to detect cache line size with: sysconf(_SC_LEVEL1_DCACHE_LINESIZE); At least on glibc-based systems. But 64 bytes is a good default nowadays. I seem to recall encountering some P4-based Xeons with 128-byte cache lines, but those are probably obsolete/rare enough to not matter.