Upgrading 1.5 year old computer

[Zelpo]

Howdy folks

Running (what is now) an older system on XP OS:

P5B-E mobo
E6300 proc
EVGA 8800 GTS 320MB vid
Corsair XMS2 2x1 GB DDR2 ram
Seasonic 600w ps, Seagate 320GB HDD (7200rpm), Antec900 case (fans on medium)

Would like to upgrade while I can on current motherboard.
Note: I don't OC, but also not opposed to it. I'm just lazy and use the plug & pray method, hook stuff up and hope it works. Not much of a bios dabber, again not opposed (for example: bios updating)

I play Civ4 way more than I should, and this game is the limiter on my system. Can't play large maps as computer lags hard between turns. My goal is to play this game on any size map without issue/lag.

Okay, my thoughts and please pick this apart because I haven't kept up with the tech for the past year so I really don't know:

Proc
Probably my biggest limiter. Keeping the FSB the same speed as the Asus (1066), my options (for dual core, which I think Civ4 doens't even take advantage of but I do have multiple web pages, word docs etc up at any one time): E7400, or more speed: what's the advantage/disadvantage to running something like a E8600 which is faster but has a different FSB speed at 1333 ?

RAM
Dang that Corsair I use is on the cheap right now. Even though XP can't take advantage of a full 4GB, should I stick a couple more of these in just to get >3GB ?

Video card
I'm lost on this one. My head swims just trying to figure it out. I'm thinking ~$400 is my price range on this item. Think an upgrade is even needed?

Thanks for your time!

[Alaron]

You can look at a list of supported CPUs on Asus.com: http://support.asus.com/cpusupport/c...Language=en-us Just search for your board. It offers a large list of new chips if you update to the correct BIOS version.

I'd go with a full 4GB. The OS will use as much as it can.

You might consider waiting on the video card to see if the CPU update helps for your games. Otherwise, right now the 9800GT+ and the Radeon HD4850 look good for the price.

[Zelpo]

I'm not up on the nomaclature of RAM speeds ... I'm currently using DDR2 800 (PC2 6400). Was checking out some 2x2GB Corsair on Newegg, but it's speed is listed as DDR2 1066 (PC2 8500). Think that'll work on a P5B-E MoBo?

[not important]

The DDR2 1066 RAM should work but the DDR2 6400 RAM would be fine. I would go with 2X2GB also.