Latency 101 문서 원본 보기

[[분류: 시스템 벤치마크]]

== Stroage Latency Comparison ==
<syntaxhighlight lang="c" line>
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns        
getpid                                      50   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD
Read 1 MB sequentially from memory     250,000   ns      250 us
Round trip within same datacenter      500,000   ns      500 us
Read 1 MB sequentially from SSD*     1,000,000   ns    1,000 us    1 ms  ~1GB/sec SSD, 4X memory
Disk seek                           10,000,000   ns   10,000 us   10 ms  20x datacenter roundtrip
Read 1 MB sequentially from disk    20,000,000   ns   20,000 us   20 ms  80x memory, 20X SSD
Send packet CA->Netherlands->CA    150,000,000   ns  150,000 us  150 ms
</syntaxhighlight>
== Instructions ==
<syntaxhighlight lang="c" line>
MOV                                           1   cycles
JMP (Short)                                   1   cycles
JMP (Far)                                 16-20   cycles
CALL (Far)                                16-22   cycles
CALL (Near)                                   3   cycles
INT                                          33   cycles
IRET                                         32   cycles
CLI                                         8-9   cycles
STI                                       16-17   cycles
RDTSC                                         5   cycles
</syntaxhighlight>

== 참고 ==
# https://gist.github.com/jboner/2841832/forks
# https://www.agner.org/optimize/instruction_tables.pdf