arpanps

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   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

arpanps

CPU

• L1 cache reference 0.5 ns
• Branch mispredict 5 ns (on a bad CPU architecture you're pretty much screwed)
• L2 cache reference 7 ns
• Mutex lock/unlock 25 ns
• Main memory reference 100 ns
• Compress 1K bytes with Zippy 3,000 ns
• Send 2K bytes over 1 Gbps network 20,000 ns
• Read 1 MB sequentially from memory 250,000 ns