Performance

1 - About

Performance has two dimensions (two metrics):

Performance is a feature.

It can sometimes difficult to talk about performance when one technique improves throughput but decreases response time.

Which has the best performance ?

Vehicle Time to Paris Speed Passengers Throughput (pk/h)
Ferrari 2 hours 250 km/h 2 500
Greyhound 5 hours 100 km/h 60 6000

This two metrics are a subset of Service Level Indicator metrics.

3 - "Time to do the task" versus "Task par unit of time"

Vehicle Vehicle Ferrari Greyhound
Speed 160 mph 65 mph
Time to Bay Area 3.1 hours 7.7 hours
Passengers 2 60
Throughput (pm/h) 320 3900
  • Time is measured in time units/job.
  • Throughput is measured in jobs/time unit.

Then <MATH>\text{time} = \frac{1}{\text{throughput}}</MATH>

The formula is only valid for one job at a time, It takes 4 months to grow a tomato. Can you only grow 3 tomatoes a year ??

4 - Rule

Minimize

The bucket list of performance gains:

  • don’t do it
  • do it only once
  • do it less often
  • do it more efficiently

Greg Rahn

Performance is a funny thing. You can't make computers faster, you can only make them:

  • do less wasted work
  • or spend less time waiting.

Baron Schwartz

5 - Quote

Within performance issues, encoding/decoding is often the most significant cost.

6 - Documentation / Reference

counter/performance/performance.txt · Last modified: 2017/09/17 18:05 by gerardnico