每個計算機工程師都應該知道的數字列表

L1 cache reference: 0.5 ns Branch mispredict: 5 ns L2 cache reference: 7 ns Mutex lock/unlock: 100 ns Main memory reference: 100 ns Compress 1K bytes with Zippy: 10,000 ns Send 2K bytes over 1 Gbps network: 20,000 ns Read 1 MB sequentially from memory: 250,000 ns Round trip within same datacenter: 500,000 ns Disk seek: 10,000,000 ns Read 1 MB sequentially from network: 10,000,000 ns Read 1 MB sequentially from disk: 30,000,000 ns Send packet CA->Netherlands->CA: 150,000,000 ns