Performance Comparisons Of Memory Copy Routines; Table; Relative Performance Of Memory Copy Routines - Intel ARCHITECTURE IA-32 Reference Manual

IA-32 Intel® Architecture Optimization
add esi,ecx
add edi,ecx
sub edx,ecx
jnz main_loop
sfence
}
}

Performance Comparisons of Memory Copy Routines

The throughput of a large-region, memory copy routine depends on
several factors:
•
coding techniques that implements the memory copy task
•
characteristics of the system bus (speed, peak bandwidth, overhead
in read/write transaction protocols)
•
microarchitecture of the processor
A comparison of the two coding techniques discussed above and two
un-optimized techniques is shown in Table 6-2.

Table 6-2

Relative Performance of Memory Copy Routines

Processor, CPUID
Signature and
FSB Speed
Pentium M processor,
0x6Dn, 400
Intel Core Solo and
Intel Core Duo
processors, 0x6En,
667
Pentium D processor,
0xF4n, 800
6-52
Byte DWORD
Sequential Sequential
1.3X 1.2X
3.3X 3.5X
3.4X 3.3X
4KB-Block
SW prefetch + HW prefetch
8 byte + 16 byte
streaming streaming
store stores
1.6X 2.5X
2.1X 4.7X
4.9X 5.7X