Benchmarks, Site Speed and User Experience

Following on the back of my recent posts looking at the (hopefully) best and worst of benchmarks I thought it would be useful to finish off with some genuine tips for creating 'lightning fast' websites. I probably lack the experience and insight to bring anything new to the table though so instead I'll point you to a selection of interesting articles.

Firstly, let's lay the benchmarking issue to rest. Ben Ramsey, who after his initial outrage at my 7 tips post felt it "actually is really humorous" (probably unjustified praise but thanks anyway!), has a nice post highlighting the code in the PHP source confirming the lack of any difference I demonstrated in my follow up post. Wez Furlong commented on my 7 tips post and highlighted a post he made on benchmarking back in 2005. For anyone feeling my method was excessive his approach gives speedier results. Personally I'd like to see it run in triplicate though.

Next, as far as the minute differences the 'lightning fast PHP'-style posts are too often built around Ilia Alshanetsky probably has the best write-up.

Please keep in mind that these are not the 1st optimization you should perform. There are some far easier and more performance advantageous tricks, however once those are exhausted and you don't feel like turning to C, these maybe tricks you would want to consider.

Absolutely.

Getting to articles with tips for that 1st round of optimisations you may want to make there are 13 tips for high performance websites on the Yahoo! developer network. These were written by Steve Souders who, in addition to writing the book 'High Performance Web Sites,' is speaking at the FOWA conference next week. That's one session I definitely want to catch. Hasin Hayder has a follow up post which is definitely worth reading.

Hasin goes into more detail than the Yahoo! article and provides some sample code. A three part series of posts at the IBM developerWorks site takes a PHP focused look at high performance websites and provides some useful instructions on setting up your sites to use the XCache opcode cache, Xdebug and memcache.

Three rules for high performance web sites

For those wanting the abridged version here are my 3 tips for high performance.

1) Fast environment - Start from a position of strength. I didn't post the average speeds in the better benchmarks post because I was looking at the difference rather than the absolute values but the benchmarks were running ten times faster on my web host than on my desktop. There are various reasons why this may be the case, Linux vs Windows XP, system specs, PHP 5.2.3 vs 'evil' PHP 5.2.1, but it doesn't really matter beyond illustrating the need for a good server and host. Other things to consider include an optimizer/opcode cache and gz compression.
2) Cache everything - Database and web service queries, blocks of content and even your entire page are all fair game.
3) Test everything - Time your code. Profile your code. Test your assumptions (including tips 1 & 2).

Speed doesn't matter

Finally an alternative take because playing devils advocate is fun. Download speed is not how users determine the speed of a site. To the user a site is fast if they can quickly achieve their goal. Steven O'Grady at Red Monk also raises some interesting points contrasting the perspective of the developer and the user.

As always further suggestions, alternative viewpoints and discussion are welcome in the comments below.