Software Prefetches PAPI_PRF_SW Retired software prefetches. x86 and x86_64 There are various kinds of software prefetches on x86/x86_64. Four of them came with SSE1 (note this is implementation specific; on AMD prefetcht0/t1/t2 all do the same thing, and on intel P4 tends to treat them differently than others): PREFETCHNTA - non temporal, meaning you plan to use it once and never again PREFETCHT0