Originally posted by Mr. Belvedere
[B]mmm , raw speed.
i'm not to keen on the extra power plug though , why can't they make cards with good power consumptions ? [/B]
My guess is that it has nothing to do with the power consumption of the chipset itself. Unless 1394b is radically different from 1394a, the spec allows external devices to draw something like 18 watts of power from the 1394 connector. Now multiply that by 3 (18W per connector) and you are way over the PCI spec for power per slot, unless you supplement the power by bringing it in with an extra power plug. Compare this to the USB spec which only allows around 2.5W per port (500mA @ 5V), and you can see that you could run some serious devices off of the Firewire bus without the need for those annoying external power transformers (i.e. wall warts).
The plug is optional...most common 1394 devices (drive enclosures, card readers, camcorders, etc.) will work just fine if you don't connect the auxiliary power. I don't know of any devices off the top of my head that need that kind of power, but I'm sure there must be some.