I finally found a way to work around the issue on my macbook Pro, so I thought I would talk about it.
The problem : my mac is very slow to go to sleep. When you close the lid, the small white light on the front is on, and instead of staying on few dozen of seconds (then starting glowing), it stays on, and take ages (1 minute) before glowing.
What happens exactly ? As soon as the lid is closed, the system starts writing down on the hard drive the content of the memory. That's to provide the ability to wake up even after a power failure. During that time, the white light stays on, and it is recommended that you don't move your laptop (the hard drive is heavily used for writing) When it's done, the white light starts "glowing".
Try it yourself : take your mac (if you don't have one, go buy one now, it's a good way to spend money anyway), close its lid, wait until the whit LED glows, then remove the battery. Plug the battery back in, then open the laptop so that it wakes up, and see the laptop wake up from so-called "Safe Sleep". Here is what it looks like :
For unknown reasons, my mac takes quite a lot of time to dump the content of the RAM to the hard drive. I believe it's a small hardware issue, as reinstalling Mac OS X from scratch didn't help. It's a small step back compared to the powerbook or ibook, which went to sleep very quickly - few seconds - and was pretty reliable. Why are the intel based laptop slower to go to sleep ?
That's because the powerbook and ibook didn't have (afaik) the "Safe Sleep" mode (which is called by normal people "suspend-to-disk") feature.
The good news : we can actually switch back and forth between the different sleep mode on the intel based mac. It works on my macbook Pro, I'm fairly confident that it will work on ibooks too. The comand is called : pmset (here is a link to its man page). I read a nice blog entry explaining how to fiddle with the "Safe Sleep" mode
The solution for lazy people is however to use Smart Sleep.prefpane . It allows you to switch between normal sleep and memory only sleep, and introduce the smart sleep feature, where the system will decide which sleep mode to use depending on the level of battery left. Neat !
