$700 Gaming PC

[polishboy1098]

Currently my PC doesn't play games too well. IT's a 2009 Emachines with the following specs

Athlon X2 250u
Some Emachines mobo
4gb ddr2
geforce 6250 se integrated
750gb Seagate

So i'm debating on whether to upgrade the Emachines or to just make a new build. If i upgraded I would add two 6870s in Crossfire, Athlon X4 640 propus, and a 700w psu.
Or i have two builds i'm debating about, the first is a SB i5 2500k build the second is a new athlon x4 640 propus.
i5 build

Intel Core i5-2500K
HD 6870
Gigabyte Z68 D2H
8gb Corsair 1600
Cooler master gx750w
WD 500gb 7200rpm
cooler master hyper 212 plus
$700 after MIR

X4 Build

AMD Athlon II X4 640
MSI 760GM-P23
G.SKILL Value Series 4GB 240-Pin DDR3 SDRAM DDR3 1333
Hd 6870 x2
Seagate Barracuda 7200.12 ST3500413AS 500GB 7200 RPM
Thermaltake A4022 92mm CPU Cooler
CORSAIR Gaming Series GS700 700W
Cost $650 after MIR

If i upgraded it would cost $475 after MIR

Would all of these builds be able to get me 40-50 FPS on battlefield High setting on a 1680 x 1050 I would just upgrade if that could get me 40 FPS, because that's about the minimum I would like.
Also i'm not sure if it's my processor or my mobo but my processor is stuck at 1.6 ghz and it won't let me overclock.

 

[Red Team FTW]

You can't upgrade an Emachines OEM to CF 6870 you have to do a new build from scratch that being said stay away from Athlon and get a Phenom II x4 955 at leased and 6870 CF will get you 60+FPS in BF3

 

[sosofm]

A good build. Change that 700W Corsair with 600W Corsair and you will cut a little the price.

 

[polishboy1098]

The Psu comes in a bundle so if I switch it to a 600w it only saves me $6, and I'd rather have the extra wattage.

 

[polishboy1098]

What build would be better then, the i5 or x4? Also would the x4 build last me awhile or would the processor become outdated?