Upgrading my computer to play Dayz

[ryanlueders]

CPU: Intel(R) Core(TM) i3-3220 @3.30GHz
GPU: AMD Radeon HD 7700 (yes its a 7700 not a 7770 and idk where I got it either)
Power Supply: 400W
Motherboard: B75M-DGS
Additional information: I think my dayz lags becase of my AMD Radeon HD 7700 becase I did some research and I heard that Radeon cards tend to have lag spikes and that is exacly the lag I experence. Yes I know Dayz requires a i5 but If I was to just throw on a EVGA GeForce GTX770 SuperClocked with EVGA ACX Cooler, 2GB GDDR5 256bit would it cut it be be able to run dayz at a CONSTANT 30 fps (with absolutly no drops) in towns like Berinzino, Electro, Balota with lowest settings and with relolution at 100 percent (1920x1080)?

 

[ryanlueders]

I forgot to mention I will also add a Corsair CX Series 600 Watt ATX/EPS Modular 80 PLUS Bronze ATX12V/EPS12V 552 Power Supply CX600M or do I not need to?

 

[ss202sl]

It's a 7700 series?
http://www.amd.com/en-us/products/graphics/desktop/7000/7700#

 

[Interocitor2]

AMD Radeon HD 7700 (yes its a 7700 not a 7770 and idk where I got it either)

No, there is no 7700. There is a 7730, 7750, 7770 and 7790. They're the 7700 series.

 

[ryanlueders]

Excuse me Interocitor2 I just read GPU-Z and you are correct GPU-Z reads AMD Radeon HD 7700 SERIES so yes you're right but considering GPU-Z dosent even tell me what GPU I have exacly how would I go about finding this out? I looked at my GPU it self and I don't even think it has its name on it.