disk defragmentation


Windows has a disk defrag tool build in. Just click on the disk and get properties, then under Tools tab. I am a efficiency nerd, but don't really trust defrag tools as it can corrupt your files. (sure i have backup, but to invoke it is a pain) Since Microsoft bundles it with Windows and this is 2009 not 1990s, i suppose it is safe, but still. Also, i always do partition my drives, but on this machine it's just one volumn of 685 GB. Usually partitioning is best done when you just bought the machine. But with PC today, it doesn't comes with a Windows installation disk anymore, so it's more difficult and i haven't partitioned my drives. Anyhow, on the Mac, the system does not bundle a defrag tool, and i always wondered why not.

Wikipedia Defrag has some thing to say about this:

HFS Plus (Mac OS X) In 1998 it introduced a number of optimizations to the allocation algorithms in an attempt to defragment files while they are being accessed without a separate defragmenter. If the filesystem does become fragmented, the only way to defragment it is to purchase a utility such as Coriolis System's iDefrag; or to wipe the hard drive completely and install the system from scratch.

umm... a optimized algorithm. One wonders, if Apple can solve the frag problem, then Microsoft probably would have done so too. I'm a bit skeptical that Apple's file system actually do any significantly better than Windows about the frag problem. The disk frag problem isn't really something that can be solved by “optimized allocation algorithm”.

google on web master things


Google did a experiment on how speed effect users. Interesting reading. Speed Matters (2009-06-23) by Jake Brutlag. Source

A more informative article with clear summary is here: Bing and Google Agree: Slow Pages Lose Users (2009-06-23) by Brady Forrest. Source

Of course we all know that we don't like slow pages, but the interesting thing is that even a 0.4 sec delay has measurable impact.

Another, about minor and major experiments google is doing: Search experiments, large and small (2008-08-26) by Ben Gomes. Source

More readings: http://googleblog.blogspot.com/2008/08/search-quality-continued.html. A interesting thing on the site is this link: http://www.google.com/jobs/britney.html, showing the few hundred variation of spellings people used to search Britney Spears. From this, we can infer how much trouble they take just for the spell correction feature, and further, how extremely complex the search technology actually is, beneath the extremely simple interface.