Simple Code, High Performance

> Speak for yourself; most phones I see still take 2+ seconds to open some apps. Why is that though? I've written code since the 8 bit days of BBC micros and ZX Spectrums. Casey Muratori's (who has been on here a lot lately) talk nails it [1] - developers just don't realise how fast their code could and should run. And the fact that we have layers upon layers of frameworks and no one cares. [1] [VIDEO]

The timing of this is great! I just watched Casey Muratori's lecture, "Simple Code, High Performance"[1] and its follow-up videos[2, 3]. I highly recommend watching it. It is about Software Optimization, and gives practical and high-level understanding of topics like CPU Architecture, SIMD etc. [1] [VIDEO] [2] [LINK] [3] [LINK]

Thank you for the detailed explanation! It sounds like programming computers back then would have been a joy. Casey Muratori's talks[0] on performance and optimization sparked an interest in me to start putting thought into what the CPU actually does (which wasn't taught when I learned web development). Since discovering his talks, I've been on the hunt for more learning materials. [0] [VIDEO]

For one real application of blue noise in particular, see [VIDEO] (22:30 is a good starting point). Here Casy explains a grass planting algorithm for games, where white noise wouldn't be suitable.

Most software in the industry is slow because it's doing a lot of stuff that it shouldn't. Often times additional "optimization" layers adds caching, but makes getting to the root of the issue harder. The biggest win is primarily getting rid of things you don't need and secondarily operating on things in batch. My playbook for optimizing in the real world is something like this: 1. Understand what you're actually trying to compute end-to-end. The bigger the chunk you're trying to optimize, the greater the potential for performance. 2. Sketch out what an optimal process would look like. What data do you need to fetch, what computation do you need to do on this, how often does this need to happen. Don't try to be clever and micro-optimize or cache computations. Just focus on only doing the things you need to do in a simple way. Use arrays a lot. 3. Understand what the current code is actually doing. How close to the sketch above are you? Are you doing a lot of I/O in the middle of the computation? Do you keep coming back to the same data? If you want to understand the limits of how fast computers are, and what optimal performance looks like I'd recommend two talks that come with a very different perspective from what you usually hear: 1. Mike Acton's talk at cppcon 2014 [LINK] 2. Casey Muratori's talk about optimizing a grass planting algorithm [VIDEO]

Casey Muratori started a whole educational webseries about this - the fact that hardware is getting faster and faster but the user experience seems to be staying the same. [VIDEO] He also has a "performance-aware programming" series: [LINK]

There are no tricks, you just have to give up mountains of levels of abstraction accumulated over the years. [VIDEO]

Blue noise is useful in games for generating more natural looking scenes. Here's an example of how to algorithmically place grass in the game "The Witness". [VIDEO] So if you use white noise, it looks unnaturally clustered with patches. This is the part that discusses the noise. [VIDEO]