First time builder. long time user/upgrader

So here's my issue! I've always bought manufactured PC packages and upgraded ram/psu/gpu/soundcards on an as needed basis. I think I can handle building my own PC now so certainly would like to give it a try. I have a general idea of selecting PC components and have read through several guides but haven't seen anything that fits my exact needs really. This psu is the current PSU I bought when I bought my hd3850 512mb pci-e card. Those were my most recent/current upgrades that I would bring over with me.

My current PC is a dimension 9100 with a p4 3ghz chip and 2 gigs of ram. GPU of course is the 3850 as previously stated.

My end goal by february, is to be able to crossfire 2 4850's or 2 3850's depending on whats financially easier at the time. Will my current PSU support this type of goal? I'd LIKE to do some amateur video editing for gaming purposes, and speaking of gaming... the majority of my PC time will be spent on it for Warhammer Online, so really building around those 2 major things there. I'd thought about quadcore because I'd like to do the video editing but I've been told some core 2 duo's can do it just fine, especially if I'm only interested in doing amateur work right now. getting my feet wet so to speak.

Sooo to sum things up, I have a keyboard/mouse/speakers/monitor(22.5"widescreen - common reso run at 1860x1050)/gpu/possibly a psu. This leaves me needing a case/mobo/cpu/memory/dvd/cd drive/harddrive.. anything else I am missing off the cuff right now?

Is it possible to come up with a build that has the potential to be above average once I get the upgraded gpu's down the road, for a price of 400-600? Would love any ideas/advice on this, especially being new tho it.

SAMSUNG Black 22X DVD+R 8X DVD+RW 16X DVD+R DL 22X DVD-R 6X DVD-RW 12X DVD-RAM 16X DVD-ROM 48X CD-R 32X CD-RW 48X CD-ROM 2MB Cache SATA 22X DVD Burner - OEM
http://www.newegg.com/Product/Prod [...] 6827151171

Western Digital Caviar SE16 WD6400AAKS 640GB 7200 RPM 16MB Cache SATA 3.0Gb/s Hard Drive - OEM
http://www.newegg.com/Product/Prod [...] 6822136218

GIGABYTE GA-EP45-DS3R LGA 775 Intel P45 ATX Intel Motherboard - Retail
http://www.newegg.com/Product/Prod [...] 6813128344

mushkin 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail
http://www.newegg.com/Product/Prod [...] 6820146731

Intel Core 2 Duo E8400 Wolfdale 3.0GHz 6MB L2 Cache LGA 775 65W Dual-Core Processor - Retail
http://www.newegg.com/Product/Prod [...] 6819115037

Antec Three Hundred Black ATX Mid Tower Computer Case - Retail
http://www.newegg.com/Product/Prod [...] 6811129042

PC Power & Cooling S61EPS 610W Continuous @ 40°C EPS12V SLI Certified CrossFire Ready 80 PLUS Certified Active PFC Power Supply - Retail
http://www.newegg.com/Product/Prod [...] 6817703005

This comes to $658.89 - $60 MIR and $20 coupon = $578.89

If you need an operating system, add $100 for:

Microsoft Windows Vista Home Premium SP1 64-bit English for System Builders 1pk DSP OEI DVD - OEM
http://www.newegg.com/Product/Prod [...] 6832116488 $99.99

The P45 chipset will support crossfire, but at x8/x8 speed. If you are looking for full speed crossfire you should look at the X48 chipset, but it won't fit into this budget very well.

This is also assuming you wanted to add your upgraded graphics cards later with a separate budget.

also, I'd read that info is processed faster w/ 1g sticks than w/ 2g sticks. is this true?

Current graphics cards run at a 16x link speed. When using the P45 chipset in crossfire mode, this drops to a 8x link speed for each card. The speed difference is minimal in most cases. I think this impacts the very high-end cards running at very high resolutions the most. With the 4850 at your resolution, the difference would probably not even be noticeable. The X48 chipset boards can run crossfire at a full 16x link speed in crossfire mode, but cost a lot more. You can look into some of these boards and see if you think the price difference would be worth it for you. You can also look at the X38 chipset if you would like. It's a little older, but also runs cards at full 16x crossfire speeds.

To answer your other question - if there is a difference in speed between 2x2 vs 1x4, it is also minimal. Your best option is to go with a 2x2 configuration. Not only does this still allow the option to step up to 8 gig in the future, but 4 sticks put more strain on your motherboard than 2.

I recently had to deal with this. I originally built my computer with 2 gig and 32-bit Vista. I recently upgraded to 64-bit Vista and 4 gig. I decided to just add an additional 2 gig instead of replacing my RAM that was working fine. I had been running my 2x1 setup at 800MHz at 4-4-4-10 timings with 2v. The added strain of 4 modules required that I change my timings to 5-4-4-12 at 2.1v to maintain stability.

How does this look for a modified build?