32/64-Bit 80x86 Assembly Language Architecture

Special ( Non-Temporal ) Memory Instructions

To understand these special memory instructions better one first needs to understand some terms:

Temporal data Memory that requires multiple accesses and therefore is loaded into a cache (as a default) for normal access.

Non-temporal hint An indicator to the processor that memory only requires a single access (one shot). This would be similar to copying a block of memory or performing a calculation, but the result is not going to be needed for a while so there is no need to write it into the cache; thus the memory access has no need to read and load cache, and therefore the code can be faster!

For more information, see Chapter 18, "System," for more information related to the cache.

MOVNTx Copy Using Non-Temporal Hint

Mnemonic

P

PII

K6

3D!

3Mx+

SSE

SSE2

A64

SSE3

E64T

MOVNTDQ