Comment by userbinator | Hacker News Reader

Comment by userbinator | Hacker News Reader

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I agree completely. Hardware has gotten orders of magnitude faster, yet the experience, as a user, hasn't changed nearly that much. You'll probably find this comparison interesting: http://hallicino.hubpages.com/hub/_86_Mac_Plus_Vs_07_AMD_Dua...

I think the saying that programmer time is more expensive than machine time is, like the quote about premature optimisation, responsible for promoting an inherently wasteful culture in programming when people are taught to take them at face value; looking at it another way, power isn't free, and when machine time translates to user time, then the situation definitely changes. I always keep in mind that users are using the software I create to do work, and their time is just as valuable if not more so than my own, especially if there are more of them. To me, it's a question of balancing the tradeoffs --- it's not worth spending a day to optimise software that will save a few minutes across all its users over its lifetime, but it is very well worth it to spend a week to optimise something so that it may save a year or more of its users' time. Whenever a programmer complains about certain tools (e.g. compiler, IDE, etc.) being slow, I keep that in mind to mention the next time he/she flippantly dismisses a time-saving optimisation using the "my time is more expensive" excuse. Programmers are users too. :-)

"Hardware has gotten orders of magnitude faster, yet the experience, as a user, hasn't changed nearly that much."

I see what you mean, but I feel that this misses out an important fact - a lot of those speed increases are only available if you modify your code to use an optimized path. Memory I/O is a classic example - it has sped up a lot but only if you make sure that you aren't generating cache misses on every memory access. Branch-prediction-friendly code is another good example that can make a huge difference to the performance of a system.

That means that a lot of the performance gains that we have achieved (not all, certainly, but a substantial chunk) are not necessarily made available to naively-written code. It is not terribly surprising then that we sometimes struggle to achieve the speed-ups the hardware has made available to us.

This problem is only compounded by the fact that performance is one of the leakiest things going when we are talking about abstraction layers. It makes things extremely difficult to think about because you need to know intimate detail of your entire software stack, which these days is huge, if you wish to effectively optimize your code.

Found this gem in the linked article: Windows Vista demands enough real estate on your hard drive that you could easily fit 30,000 full-length novels into it.

A nitpick: a day of work, say six hours, is only 3600 minutes. If you can optimize some task to save a few minutes per user, it only takes a few thousand users to be worth it.

However, I think the worst optimizations to leave on the table are in an area many developer-types won't think about: usability. We can save much more of a user's time by creating simple, intuitive interfaces than we can checking cache misses (in most modern development).

> We can save much more of a user's time by creating simple, intuitive interfaces than we can checking cache misses (in most modern development).

And at least for regularly-used software, you can save even more user time by not optimising for the first five minutes of usage but for the long-term usage. Keyboard shortcuts are a good example for this: They are mostly not simple and certainly not intuitive per se (why does Alt+Tab switch windows in particular?), yet once you know them, they do save a lot of time.

> Windows Vista demands enough real estate on your hard drive that you could easily fit 30,000 full-length novels into it.

That's an apples to oranges comparison if I ever saw one. It says nothing about whether Vista is bloated for the features it provides, by itself.

six hours, is only 3600 minutes

You mean 360.

In terms of balancing tradeoffs, I continue to find this cheat-sheet useful whenever the topic comes up.

http://xkcd.com/1205/

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