Precisely one week after it was launched, my copy of Mac OS X 10.6 "Snow Leopard" landed on my desk at work. Apple claim to have posted it last Friday, but the bank holiday weekend and postal strikes have conspired to keep me waiting this long.

On my recent Mac Pro it installed in 28 minutes and recovered a startling 31GB of disk space. I'm not quite sure how it managed that to be honest, as it's a lot more than most others are reporting. [Update: actually I suspect it's because Apple have changed the definition of a GB for Snow Leopard, so my comparisons of space used before and after are not comparing like for like. Now 1GB = 10^9 = 1,000,000,000 bytes, whereas previously it was 2^10 * 2^10 * 2^10 = 1024 * 1024 * 1024 = 1,073,741,824 bytes.]

That same Mac Pro is also capable of booting into the 64 bit kernel by holding down '6' and '4' during boot. You can check it's worked in System Profiler, where on the Software page it should say  "64-bit Kernel and Extensions: Yes". I've not noticed any abnormalities and supposedly it might run a bit faster this way, so if it stays good then I'll probably set it to 64 bit kernel permanently.

Note that only XServe machines boot with the 64 bit kernel by default, and many 64 bit Macs (like older Core 2 Duo MacBooks) can't do so because they lack 64 bit EFI (Extensible Firmware Interface).

In general I like Snow Leopard – it's the same as Leopard but all round snappier and a bit nicer. Some changes confuse me though. Take the new arbitrarily styled menus for dock items, as shown below. Nothing else in the system looks the same, and that's probably a good thing because it's hard to read, with the section heads and tick marks being far too low contrast. They're almost invisible! A real UI own goal if you ask me. Maybe they designed it before they set the gamma to 2.2…