2 GPUs better than one?

Hardware Hub GPU
1

Sorry if this is a no brainer I am new to building my own computers and thanks for the help. 

I just built a system with a Asus-Radeon HD7770 with dual monitors and its still slow. I have a GeForce 8400 laying around and I was wondering if it would boost performance if I put the GeForce and the Radeon in my system. 

For reference    

My system specs -----

Intel 3770K 4.5 GHz--CPU 
8Gb of Ripjaws Memory 
250Gb HDD
Asus HD 7770 2Gb--GPU 
ASUS P8B75-V--Motherboard 
5 120mm Fans-- 92mm Hydro CPU Heatsink 

Radeon ---- <http://www.newegg.com/Product/Product.aspx?Item=N82E16814121642&nm_mc=TEMC-RMA-Approvel&cm_mmc=TEMC-RMA-Approvel-_-Content-_-text-_->

GeForce ----<http://www.newegg.com/Product/Product.aspx?Item=N82E16814187168>

2

Nope. having two GPUs only helps if you use SLI or Xfire, which requires two of the same GPU.

3

no, mixing amd/nvidia gpus isn't really possible (ok it's "possible" but pointless)

for multiple gpu (adding more of the same gpu) it's not really a good idea, single gpu is just better

but what do you mean by "slow"? slow rendering in an application(which)? poor gaming performance? just general lag/latency/roughness in windows? what?

4

What I mean by slow is that when I have more than 2 programs running my screens freeze and go black for like a minute or two then they come back on and its fine. This is happening more and more often and I don't know why i thought it was the GPU because it has to do with the screens. 

Any help or tips would be much appreciated. I just spent 1000 dollars on a system that is freaking out. HELP.

5

you have a problem, i don't know what it is, but you have a problem, maybe the 7770 is dying