Copied from CppCon 2014: Chandler Carruth "Efficiency with Algorithms, Performance with Data Structures" near 37:50
| type | time | time | relative |
|---|---|---|---|
| Once cycle on a 3 GHz rocessor | 1 ns | ||
| 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 refrence | 100 ns | 20x L2, 200x L1 | |
| Compress 1k bytes with Snappy | 3,000 ns | ||
| Send 1k bytes over 1 Gbps network | 10,000 ns | 0.01 ms | |
| Read 4k randomly from SSD* | 150,000 ns | 0.15 ms | |
| Read 1 MB sequentially from memory | 250,000 ns | 0.25 ms | |
| Round trip within same datacenter | 500,000 ns | 0.5 ms | |
| Read 1 MB sequentially from SSD* | 1,000,000 ns | 1 ms | 4x memory |
| Disk seek | 10,000,000 ns | 10 ms | 20x datacenter RT |
| Read 1 MB sequentially from disk | 20,000,000 ns | 20 ms | 80x memory, 20x SSD |
| Send packet CA->Netherlands->CA | 150,000,000 ns | 150 ms |