Title: System Design Primer: Appendix
Date: 2020-05-27
Status: draft
Summary: Appendix
CoverImage: http://i.imgur.com/6SbxQah.png
Thumbnail: http://i.imgur.com/oCWLuMC.png

## Appendix

You'll sometimes be asked to do 'back-of-the-envelope' estimates.  For example, you might need to determine how long it will take to generate 100 image thumbnails from disk or how much memory a data structure will take.  The **Powers of two table** and **Latency numbers every programmer should know** are handy references.

Title: System Design Primer: Appendix
Date: 2020-05-27
Status: draft
Summary: Appendix
CoverImage: http://i.imgur.com/6SbxQah.png
Thumbnail: http://i.imgur.com/oCWLuMC.png

## Appendix

You'll sometimes be asked to do 'back-of-the-envelope' estimates.  For example, you might need to determine how long it will take to generate 100 image thumbnails from disk or how much memory a data structure will take.  The **Powers of two table** and **Latency numbers every programmer should know** are handy references.

### Powers of two table

```
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
```

Add powers of two table
Add powers of two table
