Crossfire or just a new video card?

[caggles]

Hey all!

I'm building a gaming computer (my first) and I have essentially what I want mapped out. The parts look like this:

ASUS AMD 790GX/790FX Motherboard
AMD Phenom II X4 940 Deneb 3.0GHz Processor
ASUS Radeon HD 4870 512MB Video Card (with Crossfire support)
OCZ Reaper 4GB (2 x 2GB) DDR2 1066 RAM

First, I want people's opinions on the system. Is there any grossly over- or under-powered part compared with the rest? I think I evened it out pretty well, but like I said, it's my first build.

Anyways, the actual question is this:

I can get one of 2 motherboards:
790GX or 790FX. As far as I can tell, the only different between the two (other than $70) is that the FX can support crossfired dual and even triple x16 video cards, whereas the GX can support only 1. My video card is x16 and I don't plan on replacing it particularly soon. So: would it be worth the extra $70 to buy the FX and then just plop another x16 video card into the motherboard once I need to, or would I be better off just getting the GX and replacing the video card with an upgraded version later? Multiple opinions on the matter would be nice!!

Thanks for the help!!

~~caggles

 

[caggles]

Oh ya, one more thing: how much power is this thing going to need? Right now I'm budgeting for a 700W power supply, but that could be overkill. I have no idea what I should expect here.

 

[DiscoDuck]

Unless you plan to game at resolutions beyond 1920x1080, there is no need for crossfired 4870's. It wouldnt hurt to go with the 1 gig version if you want a little more video power for games. 700 is more than enough if you buy a good name brand psu. Most people like pcp&c, corsair, antec. Just do a little checking to make your power supply gives the required 12v amps and connectors the video specs says it needs.

 

[jennyh]

It would probably be better to buy the 1gb 4870, I know I wish I had.

700w is easily enough, even with crossfired 4870's.

If you are looking to save money on the system, just buy standard 800mhz RAM. It truly makes no difference. It looks like you are building a Dragon system with your choices but FX and even 790X mobo's will work just fine as well. AMD say that the GX gives the best performance, but most enthusiasts would disagree and choose the FX. So long as it's a 790 you'll be good. There are 790X mobo's around that are a *lot* cheaper than GX or FX so check them out. Gigabyte do 3 I think, the UD 4/5 seem really good value for money.

My friend just built a Dragon system tonight with similar specs to yours. It's pretty amazing I have to say.

 

[caggles]

I was originally planning on getting the 800mhz RAM, but this RAM is only $20 more, so I figure I might as well

Thanks for the advice everyone. I'm pretty sure I'll be going with the GX, and then take that money I saved to get a 1gb video card instead.

You guys are awesome!! Thanks so much!!