I have acquired a 30" flat panel monitor...my last build has been quite the trooper and carried me through 4 years (with some relatively easy upgrades), but alas, it can no longer cut the mustard.

I have completely lost touch with the developments in personal computer components and need some help putting together an Assassins Creed @1920x1600 @ 50+ fps kind of rig. The thing I really want help on is avoiding waste. Budget is flexible (2,500?), but I want to put something together that is not lopsided or wasteful (i.e. more memory, CPU or Graphics Card than the other components can handle), has a clear path to expansion when needed (Open DIMM slots, GPU slots, enough power...), and isn't too loud. My last one roared.

I will boot (and need to buy) Vista and MS Office and will use the machine for music, the occasional movie, and typical office tasks. I do not think that any of my other components are salvageable...and I am going to pass it onto a brother who needs it.

Lastly… I am not going to tweak this one. Fun to do, but I just don’t have the cycles to focus on it like I would like to.

The tenacity with which you guys help folks with their builds on this site is amazing. I thank all of you in advance for the help.

just so you know, 30" resolution is 2560x1600. and as for the computer, i think a Q9550 with an X48 board, along with 4GB of DDR2 800Mhz ram and 2 4870x2's in crossfire. at that resolution, you'll need the power in the gpu's but you could skimp on the cpu a bit. you could get by with an E8400, and if you overclock it to maybe 3.6-3.8Ghz, it'll be plenty fast. as for noise, just get a good quality power supply. good ones generally have higher quality fans which don't make as much noise.

A single 4870x2 will do, quadfire doesn't scale that well. Then you won't need an expensive x48 motherboard, a P45 based one will do, and a Q9450 is also just fine. 4GB+ RAM a must. Remember to get a 64bit OS

yeah that would be more cost effective than what i posted.

A 30" monitor should have a native resolution of 2540x1600, or at least the ones I know of do. I think you will want to run it at that resolution. I had a Samsung 305T working at that resolution with a 8800GTS-512. Playing civilization-4 was just fine at highest details. That is not exactly a FPS, but I don't think you need to go overboard. The biggest impact on performance will be the vga card, not the cpu. Currently the top single card is the 4870X2. The GTX280 is not far behind. Read this article, and see where you might fit: http://www.guru3d.com/index.php?page=vga_charts

As to the cpu, a E8500 will play better than a quad, unless your game is optimized for more than two cores, like FSX or supreme commander. Most games do not require a quad to play well. Game developers will not sell as many if they do. I don't forsee that changing for a while.

4gb is good, and will play better than 2gb.

I don't like planning on sli/crossfire. You pay more up front for the motherboard and psu, with no guarantee that buying a second card in the future will be a cost effective thing to do. I think it is better to just plan on selling your old top of the line card, and replacing it with the next generation card.

You should have no problem with your budget, and no doubt there will be many here who will tell you how to spend it.

You say you don't want to overclock, thats what i also thought. It's really easy and there's a ton of guides available to help.
Running my rig oc'd for a while now, no problems too.

Benchmarks for Assassin's Creed here;

Cooler Master Cosmos S RC-1100 $220 Nice balance of cooling and quiet. Cosmos S review
Corsair 750TX 750W PSU $130 (plus $20 rebate) Sized for 2 4870 video cards (possible future upgrade to 2nd 4870)
ASUS P5Q-E P45 ATX Motherboard $160 (2nd PCI-e video card slot and room for 8GB total RAM)
Core 2 Quad Q9550 Yorkfield 2.83GHz $325
Muskin 4GB DDR2 800 RAM $89 (plus $20 rebate)
SAPPHIRE Radeon HD 4870X2 $275 (plus $20 rebate)
WD Caviar SE16 WD6400AAKS 640GB HDD $85
SAMSUNG 22X DVD Burner $26
OCZ ATV 8GB USB Flash Drive $39 (plus $15 rebate) modern floppy replacement and good for backing up work in progress
Vista Home Premium SP1 64-bit $100 see Vista versions compared
~roughly $1450 before rebates

1920x1200 resolution is right about the point where a 2nd video card (Crossfire or SLI) starts to make sense. But if you checked out the Assassin's Creed benchmarks you'll notice that at 25x16 res and max graphics detail with AA/AF on there really isnt much difference between the single 4870 and the dual GPU 4870X2.

I think its very safe to give a single 4870 a "test ride" and see if you're happy with the performance. You can always back off the graphics detail a smidge and get a slightly faster running game. And if you want to upgrade to a 2nd GPU you can do that. Someone is bound to point out that a P45 motherboard is dual 8 lane PCI-e channels and the X38/48 has dual 16 lane PCI-e channels and performs better. That's true and there is about a 15%-20% performance advantage in the X48 motherboard for the extra $100 they cost (plus the extra $275 for a 2nd 4870).
It's easier to think about upgrading your graphics card if you paid $275 for it than it would be if it had a ~$550 price tag.
For that reason (and because we know there are always more powerful cards just over the horizon) I think if a single 4870 meets your needs today a P45 MB and single 4870 is the best option with an eye to a future single card GPU upgrade.


alternatives:
SAPPHIRE Radeon HD 4870X2 $560 2 4870 GPUs in 1 graphics card - side steps P45's CF dual 8 lane PCI-e by using single 16 lane PCI-e slot.
ASUS Xonar DX 7.1 Channels PCIe Sound Card $95 test the built in audio first - if it doesnt meet your expectations add in a sound card

Awesome help. Thank you. I looked into the native res on the monitor and you are right on the 2560x1600. Any further suggestions are welcome. I will put together a build and post in the next week or so for comment.

I will give OCing a second look...

Is Newegg is still the vendor of choice?

Take a look at the Half-Life 2: Episode Two 2560x1600, 16xAF, DX9, Maximum Detail chart for comparison.
Single 4870 = 70max/60min vs. 4870X2 127max/118min. To me the Minimum FPS is the most important number and HL2 Ep2 has that almost perfect scaling that makes it easy to recommend 2x4870 or the 4870X2. Excellent example of good multi-GPU scaling.
Now look @ Assassin's Creed 2560x1600, 4xAA, 16xAF, DX10/10.1, Maximum Detail: Single 4870 = 35max/25min vs. 4870X2 47max/27min.
That extremely small difference in the Min score makes it hard to recommend a 2x4870CF setup or a 4870X2.

NewEgg is fast and easy to use, with lots of good info on the parts. So its used a lot as a reference to talk about the parts.
NewEgg is still a leader although not always the best price. Example: Corsair 750TX $90 a/r and free shipping @ Egg and then Corsair 750TX $83 a/r and free shipping @ Buy.com

I like WR2s suggestions. Start with a single 4870 and after a few weeks or months if you want to upgrade then switch out to a 4870x2 or add another 4870. Remaining budget might go for a quality UPS and/or other peripherals.

CrossFireX will let you mix and match video cards so you have a 2, 3 and 4 GPU options. And we cant forget the 2x4850 Crossfire option either.
More Assassin's Creed benchmarks:
Note that 2x4850CF doesnt beat out a single 4870 in the Min FPS as it probably would do in many other games.
And going to 2, 3 and 4 GPUs isnt doing all that much to improve the Min FPS performance either.
Part of the problem is poor driver support that might improve and the game's own programming - harder to expect improvements there.

So...not all games are even close to being created equal in taking advantage of (2) GPUs. What would you guess about future release games in the next year or so? Fallout 3, Warhammer Online, etc. More games taking better advantage of (2) GPU or more of the same?

More of the same IMO. Directly related to the programming skills of the developers (which is partly related to the development budget).
About the only sure thing you can count on is that the next-gen GPUs (ATI 5850/5870? GTX 360/380? LOL) will do better with the newer games.

If you ask the developers "Will Xxxxxxx support multiple core CPUs?" The will of course say yes - meaning it will run on a dual/quad core CPUs which isnt the same as saying it will have true multi-threading support and scale up well with extra cores.
Same type of response for CF/SLI support.

I can run the X48 motherboard with one GPU, correct? If I wanted to look at the (2) 4870 as the expansion path to gain 15-20% that would be the motherboard of choice, and if the path is sell the card and get the next one, the P5Q is the answer...is that straight?