Latency Chart - weixingsun/perf_tuning_results GitHub Wiki
| Unit |
Notation |
Magnitude |
| Nanosecond |
1 ns |
1 x 10-9 seconds |
| Microsecond |
1 us |
1 x 10-6 seconds |
| Millisecond |
1 ms |
1 x 10-3 seconds |
| Second |
1 s |
1 second |
Latencies
| Order |
Example |
Duration |
Scaled |
| 1st |
1 CPU cycle (register access) @ 3.3GHz |
0.3 ns |
1 second |
| 1st |
L1 cache reference |
0.9 ns |
3 seconds |
| 1st |
L2 cache reference |
2.8 ns |
9 seconds |
| 1st |
L3 cache reference |
12.9 ns |
43 seconds |
| 1st |
Mutex lock / unlock |
17 ns |
56 seconds |
| 1st |
Main memory access (DRAM, from CPU) |
120 ns |
6 minutes |
| 2nd |
Send 1K bytes over 1 Gbps network |
8 us |
7 hours |
| 2nd |
Ping over idle 1/10 Gbps network |
50 us |
2 days |
| 2nd |
SSD: I/O (flash memory) |
50-150 us |
2-6 days |
| 3rd |
HDD: I/O |
1-10 ms |
1-12 months |
| 3rd |
Internet: SF / NY |
40 ms |
4 years |
| 3rd |
Internet: SF / UK |
81 ms |
8 years |
| 3rd |
Internet: SF / Oz |
183 ms |
19 years |
| 4th |
TCP: Packet Retransmit |
1-3 s |
105-317 years |
Refer to:
Latency Numbers Every Programmer Should Know