| Operation | Latency (ns) | Latency (µs/ms) | Comparison |
|---|---|---|---|
| L1 cache reference | 0.5 | ||
| Branch mispredict | 5 | ||
| L2 cache reference | 7 | 14x L1 cache | |
| Mutex lock/unlock | 25 | ||
| Main memory reference | 100 | 14x L2 cache, 200x L1 cache | |
| Compress 1K bytes with Snappy | 3,000 | 3 µs | |
| Read 1 MB sequentially from memory | 20,000 | 20 µs | ~50GB/sec DDR5 |
| Read 1 MB sequentially from NVMe | 100,000 | 100 µs | ~10GB/sec NVMe, 5x memory |
| Round trip within same datacenter | 500,000 | 500 µs | |
| Read 1 MB sequentially from SSD | 2,000,000 | 2,000 µs (2 ms) | ~0.5GB/sec SSD, 100x memory, 20x NVMe |
| Read 1 MB sequentially from HDD | 6,000,000 | 6,000 µs (6 ms) | ~150MB/sec 300x memory, 60x NVMe, 3x SSD |
| Send 1 MB over 1 Gbps network | 10,000,000 | 10,000 µs (10 ms) | |
| Disk seek | 10,000,000 | 10,000 µs (10 ms) | 20x datacenter roundtrip |
| Send packet CA->Netherlands->CA | 150,000,000 | 150,000 µs (150 ms) |
Notes
1 ns = 10^-9 seconds
1 µs = 10^-6 seconds = 1,000 ns
1 ms = 10^-3 seconds = 1,000 µs = 1,000,000 ns