Poker rig, Quad Core build

[Gonso]

Ok, upgraded my old system. I use it for Photoshop and Illustrator heavily, and play poker. No real gaming or anything.

Went from a 3GHz P4 to the Q6600 quad core. New motherboard obv, so I replaced my AGP vid card to a new PCI-Express and so on.

Thing is, I have 2 gigs on DDR-400 ram I wanted to keep to stay in budget - I bought new drives and monitor and so on already. This board supports this DDR rather than DDR2, and it was cheap, so I can ease into my upgrade (board was $45).

Eventually, of course, I'll get a new board and load it up with a lot more of the memory. Maybe give Vista a year to sort out it's issues, whatever.

1) How big a dropoff can I expect using this memory with a new 4-core? Enough to care? When I make the switch to DDR2 will I even notice?

2) The front side bus is 1066 on this CPU, but a lot of people are using DDR2 800 memeory with it. I can't figure out why they wouldn't use DDR 1066 - shouldn't the FSB of the memory match that of the CPU?

Any input is appreciated.