Comparing two computers I need your opinion

[The_Absolute]

I want to get a new desktop computer for christmas, one of them $821, and the other is just over 1300 (both with the tax and warranty added).

The less expensive one is the Gateway LX6200, and the other, more expensive one is called the Gateway FX. My stepfather apparently isn't willing to spend the difference to get the better one (with $500 pitched in from my mother), I was wondering if the two would be similar in performance if I added a high-powered directx 10 GPU in the LX6200. The FX already has a Radeon HD 4850 installed in it, the LX6200 has a Radeon HD 3200 256 MB GPU.

Here are links to the specs on both machines.

http://www.gateway.com/systems/product/529668208.php

http://www.gateway.com/systems/product/529668196.php?tab=review&cmpid=rr

I am most concerned about the speed and power difference between the AMD Phenom X4 9500, and the Intel Core 2 quad Q9400. 2.2 GHz vs 2.66 GHz, and the LX6200 motherboard's gaming ability. I was told that a top of the line Phenom has about half the performance of a mid-range Core 2. However, the LX6200 has 8 GBs of RAM instead of the FX's 6 GB. Will the Radeon HD 3200 run games like Battlefield 2 without any hassle? Or do I absolutely have to upgrade to a really high-end GPU to run Battlefield 2 with no problems? If the LX6200 had the same GPU as the FX, would they equal in overall performance? Or would it be a lot slower because of the Phenom's slower core clock and lesser L3 cache?

I used to own a custom-built computer that had a Pentium 4 3.0 GHz, 1GB of RAM, and a Radeon X-800 PRO 256 MB. Either one of this computers would certainly be better than that. Would video games like Battlefield 2 run slower on both the Phenom X4, and the Core 2 Quad because of their lower clock speeds and Battlefield 2's inability to utilize more than a single core and it's 64-bit incompatibility? How does the Radeon HD 3200 shape up against the olde Radeon X-800 Pro? Especially when it comes to running games like Battlefield 2?
Will the game have lesser performance on both machines due to the 2005-era video games utter inability to recognize/utilize more thana a single core and it's incompatibility with 64-bit processors.

Exactly how much slower is the AMD Phenom as opposed to the Intel Core 2?

 

[RiseAgainst]

I just now saw this thread, sorry it's late. If you're still wondering I would recommend the LX6200. It's not worth the extra money to play Battlefield 2. It should run fine, from looking at the specs the only problem that I can see that you might face is running Vista. You have plenty of RAM but Vista still has bugs. I don't know how well Battlefield 2 will run on Vista but if you have problems you can probably download a patch from their website. Plus if you need to you can upgrade the processor for less than the difference between the two systems.