Numbers
- https://gist.github.com/jboner/2841832
- http://www.eecs.berkeley.edu/~rcs/research/interactive_latency.html
Latency
Memory
Operation | Time | Note |
---|---|---|
L1 ref | 1ns |
|
L2 ref | 4ns |
|
RAM ref | 100ns |
|
SSD ref | 16us |
"Random read", eq. to HDD disk seek |
HDD ref | 4ms |
Disk seek |
Read 1MB Sequentially
From | Time |
---|---|
RAM | 20us |
SSD | 300us |
HDD | 2ms |
CPU
Operation | Time |
---|---|
Mutex lock | 17ns |
Compress 1KB | 2us |
Context switch | 5us |
Network
Operation | Time |
---|---|
Send 2KB over network | 1us |
Round-trip in DC | 500us |
Round-trip CA->AMS | 150ms |
Data Speeds
Operation | Speed |
---|---|
HDD read/write | 150 MB/s |
SSD read/write | 500 MB/s |
USB 2.0 HDD | 30 MB/s |
USB 3.0 SSD | 300 MB/s |
Time
Period | Seconds |
---|---|
1 hour | 3.6K |
1 day | 86K |
1 year | 30M |
Powers of 2
Power | Size | Kibi |
---|---|---|
2^3 | 8 | |
2^4 | 16 | |
2^5 | 32 | |
2^6 | 64 | |
2^7 | 128 | |
2^8 | 256 | |
2^9 | 512 | |
2^10 | 1024 | 1 KiB |
2^16 | 65,536 | |
2^20 | 1,048,576 | 1 MiB |
2^30 | 1,073,741,824 | 1 GiB |
2^32 | 4,294,967,296 | |
2^40 | 1.09 * 10^12 | 1 TiB |
2^64 | 1.84 * 10^19 |