Aditya Rana ranaaditya

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

Keybase proof

I hereby claim:

I am ranaaditya on github.
I am ranaaditya (https://keybase.io/ranaaditya) on keybase.
I have a public key ASC1KSsMQW-vCdxQ6vaGeV-uYXdV3gMyKxw0ZLwH_4k80Ao

To claim this, I am signing this object:

People

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System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

	adb help // List all comands

	== Adb Server
	adb kill-server
	adb start-server

	== Adb Reboot
	adb reboot
	adb reboot recovery
	adb reboot-bootloader

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	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 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD

	/**
	* @author ranaaditya
	*/

	#include<bits/stdc++.h>

	using namespace std;

	struct Node {
	int data;