diff --git a/README.md b/README.md index 8a496c82..c59f2a07 100644 --- a/README.md +++ b/README.md @@ -1533,12 +1533,12 @@ Power Exact Value Approx Value Bytes --------------------------------------------------------------- 7 128 8 256 -10 1024 1 thousand 1 KB -16 65,536 64 KB -20 1,048,576 1 million 1 MB -30 1,073,741,824 1 billion 1 GB -32 4,294,967,296 4 GB -40 1,099,511,627,776 1 trillion 1 TB +10 1024 1 thousand 1 KiB +16 65,536 64 KiB +20 1,048,576 1 million 1 MiB +30 1,073,741,824 1 billion 1 GiB +32 4,294,967,296 4 GiB +40 1,099,511,627,776 1 trillion 1 TiB ``` #### Source(s) and further reading @@ -1555,22 +1555,22 @@ 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 10,000 ns 10 us -Send 1 KB bytes over 1 Gbps network 10,000 ns 10 us -Read 4 KB randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD -Read 1 MB sequentially from memory 250,000 ns 250 us -Round trip within same datacenter 500,000 ns 500 us -Read 1 MB sequentially from SSD* 1,000,000 ns 1,000 us 1 ms ~1GB/sec SSD, 4X memory -Disk seek 10,000,000 ns 10,000 us 10 ms 20x datacenter roundtrip -Read 1 MB sequentially from 1 Gbps 10,000,000 ns 10,000 us 10 ms 40x memory, 10X SSD -Read 1 MB sequentially from disk 30,000,000 ns 30,000 us 30 ms 120x memory, 30X SSD -Send packet CA->Netherlands->CA 150,000,000 ns 150,000 us 150 ms +Compress 1K bytes with Zippy 10,000 ns 10 μs +Send 1 KB bytes over 1 Gbps network 10,000 ns 10 μs +Read 4 KB randomly from SSD* 150,000 ns 150 μs ~1GB/sec SSD +Read 1 MB sequentially from memory 250,000 ns 250 μs +Round trip within same datacenter 500,000 ns 500 μs +Read 1 MB sequentially from SSD* 1,000,000 ns 1,000 μs 1 ms ~1GB/sec SSD, 4X memory +Disk seek 10,000,000 ns 10,000 μs 10 ms 20x datacenter roundtrip +Read 1 MB sequentially from 1 Gbps 10,000,000 ns 10,000 μs 10 ms 40x memory, 10X SSD +Read 1 MB sequentially from disk 30,000,000 ns 30,000 μs 30 ms 120x memory, 30X SSD +Send packet CA->Netherlands->CA 150,000,000 ns 150,000 μs 150 ms Notes ----- 1 ns = 10^-9 seconds -1 us = 10^-6 seconds = 1,000 ns -1 ms = 10^-3 seconds = 1,000 us = 1,000,000 ns +1 μs = 10^-6 seconds = 1,000 ns +1 ms = 10^-3 seconds = 1,000 μs = 1,000,000 ns ``` Handy metrics based on numbers above: