New build; a few questions

[tdavis]

Hi everyone. I'm planning on building a new gaming PC, with a budget of about $1500, though I can spend a couple hundred more if necessary. It will be used primarily for gaming, though I'll use it for any other applications requiring a lot of power (eg CAD). I already have a Thinkpad so I'll be doing a lot of my day to day computing on that.

I've decided on a few things, most notably the GPU, which is the EVGA Geforce 9800 GX2. I wanted to get some advice on a few other components

1. CPU - I'm trying to decide between the Q9450 and the E8400. One thing I'm worried about is how soon I'll need to upgrade to Nehalem. I would like to keep up a high end (not bleeding edge, but respectable) system, but at the same time I'm not going to spend much more than $400 on a CPU (unless the performance really justified it). So with that in mind, should I go with the E8400 and plan on dumping it in a year and a half if not sooner, or spend the extra $150 on the Q9450 and plan on keeping it 2+ years?

2. Mobo - I've been looking at the Asus P5Q Deluxe (Intel P45) and the EVGA nForce 780i. I'm open to any other suggestions as well. the P5Q is definitely superior, but it doesn't support SLI. I might want to throw in another GX2 sometime in the future, but I won't be buying a new mobo to do that. I'm leaning towards the nForce 780 for that reason. I'd like to get a 790, but I don't think it's worth $350+.

3. Power Supply - I honestly don't know a thing about these other than the fact that I have to get one with enough watts for my system. Should I wait until I've finalized all the other components before looking at these?


Any help will be appreciated.

Newegg links for components discussed:

Q9450
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115042

E8400
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115037

P5Q
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131297&Tpk=p5q

nforce 780
http://www.newegg.com/Product/Product.aspx?Item=N82E16813188024

Geforce 9800 GX2
http://www.newegg.com/Product/Product.aspx?Item=N82E16814130338

 

[Why_Me]

http://www.anandtech.com/video/showdoc.aspx?i=3341&p=20 <---ATI 4870 Crossfire test results.

"Crossfire Build"

Take that cpu and move up the FSB (Front Side Bus) to 3.6GHz (9x400). That's a very mild overclock for that cpu. Keep that cpu for a year or two then dump it for something better. In the meantime that build down below will run any of today's games smoothly including Crysis.

http://www.newegg.com/Product/Product.aspx?Item=N82E16811119137 $84.99
COOLER MASTER RC-690-KKN1-GP Black SECC/ ABS ATX Mid Tower Computer Case - Retail

http://www.buy.com/prod/corsair-tx-750w-atx-12v-power-supply/q/loc/101/206178325.html $109.99 Price After Rebate(s): $99.99 Shipping: FREE
Corsair TX 750W ATX 12V Power Supply - CMPSU-750TX

http://www.newegg.com/Product/Product.aspx?Item=N82E16819115037 $189.99
Intel Core 2 Duo E8400 Wolfdale 3.0GHz 6MB L2 Cache LGA 775 65W Dual-Core Processor - Retail

http://www.newegg.com/Product/Product.aspx?Item=N82E16835233001 $24.99 ($14.99 after $10.00 Mail-In Rebate)
XIGMATEK HDT-S963 92mm Rifle CPU Cooler - Retail

http://www.newegg.com/Product/Product.aspx?Item=N82E16835233019 $6.99
XIGMATEK ACK-I7751 Retention Bracket - Retail

http://www.newegg.com/Product/Product.aspx?Item=N82E16813128336 $224.99
GIGABYTE GA-X48-DS4 LGA 775 Intel X48 ATX Intel Motherboard - Retail

http://www.newegg.com/Product/Product.aspx?Item=N82E16814102748 $309.99
SAPPHIRE 100243L Radeon HD 4870 512MB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card

http://www.newegg.com/Product/Product.aspx?Item=N82E16814102748 $309.99
SAPPHIRE 100243L Radeon HD 4870 512MB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card

http://www.newegg.com/Product/Product.aspx?Item=N82E16820227267 $99.99 ($69.99 after $25.00 Mail-In Rebate)
OCZ Reaper HPC Edition 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail

http://www.newegg.com/Product/Product.aspx?Item=N82E16822148288 $89.99
Seagate Barracuda 7200.11 ST3500320AS 500GB 7200 RPM 32MB Cache SATA 3.0Gb/s Hard Drive - OEM

http://www.newegg.com/Product/Product.aspx?Item=N82E16827106263 $23.99
LITE-ON Black 20X DVD+R 8X DVD+RW 8X DVD+R DL 20X DVD-R 6X DVD-RW 12X DVD-RAM 16X DVD-ROM 48X CD-R 32X CD-RW 48X CD-ROM 2MB Cache SATA 20X DVD±R DVD Burner - OEM

http://www.newegg.com/Product/Product.aspx?Item=N82E16835186020&Tpk=mx-2 $6.99
ARCTIC COOLING MX-2 Thermal Compound - Retail

http://www.newegg.com/Product/Product.aspx?Item=N82E16832116204 $94.99
Microsoft Windows Vista 64-Bit Home Premium for System Builders Single Pack DVD - OEM

$1,597.87
$1,532.87 w/mail in rebates

 

[tdavis]

Thanks for the anandtech link. I checked out their multi gpu performance comparison and see no reason why I would swap the GX2 for the CF 4870s. Both offer tremendous performance, especially at 1920x1200 which is the resolution I'm primarily interested in. It looks like the GX2 actually beats them in terms of practical performance (ie when not comparing 120 fps to 160 fps). Regardless, they definitely aren't worth the extra $200 so I'll be sticking with the GX2.

One other thing I noticed in their comparisons is that the "GX2 SLI" performed very poorly. This is two GX2 cards in quad SLI, correct? Has Nvidia not released decent quad sli drivers yet?

As for the rest of the build you suggested, I see no reason to use X48 over P5Q or nforce 780i since I don't need CF support. I'm not sure what your reasoning behind the E8400 was. I'm considering it, but my orginial concerns about the CPU still stand. Unless I upgrade in under a year and a half, I think the Q9450 would be the best choice.