garrytan

Garry Tan's Mega Plan Review Mode

name: plan-mega-review
version: 2.0.0
description: |
  The most thorough plan review possible. Three modes: SCOPE EXPANSION (dream big,
  build the cathedral), HOLD SCOPE (review what's here with maximum rigor), and
  SCOPE REDUCTION (strip to essentials). Context-dependent defaults, but when the
 user says EXPANSION — go full send. Challenges premises, maps every failure mode,

gkbrk

import socket
import random
import time
import sys

log_level = 2

def log(text, level=1):
    if log_level >= level:
        print(text)

hellerbarde

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

jboner

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