Hi Matt
If you plan to use a firewire interface with the laptop for low-latency music stuff then avoid all laptops that
don't have a TI (Texas Instruments) firewire chipset, or ascertain as to whether the soundcard is compatible with any other specific computer firewire chipsets.
Unfortunately it's getting harder and harder to find laptops with TI firewire chipsets inside them as laptop manufacturers are turning to other fw chipset manufacturers such as Ricoh (the Dell laptops use these), O2 Micro (and these), NEC, ENE, etc. which are less stable (clock wise) and have a lower throughput (limiting the number of channels that can be used at lower latencies), unless your soundcard explicitly states they are compatible with those brands.
For the newer laptops with PCI-ExpressCard slots, the PCI-ExpressCard buss also uses the same controller as the firewire, so you can't get around the problem by merely buying a Texas Instruments PCI-ExpressCard and plugging it in and using that. Everything on that buss (cardbus/firewire) must be native TI, or whatever other firewire chipset the soundcard manufacturers exclusively state is compatible with that particular soundcard. The older PCMCIA slots (as opposed to PCI-ExpressCard) with any make should be ok with a TI card, though.
I got absolutely piss bored by looking into it as pretty much all the bigger 17" laptops I was looking into at the time have non-TI based FW/PCI-x chipsets/controllers, so it's ending up that I'm building my own desktop instead for making choons and will probably get a cheapo laptop for non-music purposes. I have a Motu Traveller firewire soundcard.
[
It's all gone a bit Ricoh crazy]
[
Discussion on various makes/models and chipsets]
[
Crappy Dell firewire]
Also the Apple Macbook Pro laptops (Apple being one who
used to use TI exclusively) will be changing their TI chipsets to another manufacturer some time soon (if not already), and I believe also the standard Macbooks may do too, so no-one's safe.
Of course if you have a USB interface, then ignore the above.