Pentium 4 について
IA-32 Intel® Architecture Optimization
http://download.intel.com/design/Pentium4/manuals/24896613.pdf
The Prefetch Instructions – Pentium 4 Processo Implementation

prefetchnta Fetch the data into the second-level cache, minimizing
cache pollution.
prefetcht0 Fetch the data into all cache levels, that is, to the
second-level cache for the Pentium 4 processor.
prefetcht1 Identical to prefetcht0
prefetcht2 Identical to prefetcht0