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chaifix / latency.txt
Created May 13, 2021 09:05 — forked from understeer/latency.txt
HPC-oriented Latency Numbers Every Programmer Should Know
Latency Comparison Numbers
--------------------------
L1 cache reference/hit 1.5 ns 4 cycles
Floating-point add/mult/FMA operation 1.5 ns 4 cycles
L2 cache reference/hit 5 ns 12 ~ 17 cycles
Branch mispredict 6 ns 15 ~ 20 cycles
L3 cache hit (unshared cache line) 16 ns 42 cycles
L3 cache hit (shared line in another core) 25 ns 65 cycles
Mutex lock/unlock 25 ns
L3 cache hit (modified in another core) 29 ns 75 cycles
@chaifix
chaifix / latency.txt
Created May 13, 2021 09:05 — forked from jboner/latency.txt
Latency Numbers Every Programmer Should Know
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