Stuttery lag on dual monitor

[Terahertz]

I just connected a second monitor to my desktop, but when I started WoW, both my screens started lagging stuttery-like. I looked up the issue on google and it seems many people had similar issues. Problem is that I tried some of the methods that supposedly fixed it, but they did not.

I'm in Win7 atm and I tried going into NVIDIA Control Panel > Adjust desktop size and position > Perform scaling on: GPU

But that did not work for me. There was also someone suggesting to have my onboard graphics card drive my second monitor? But I don't know if my desktop has that or if it's just something default on a mobo. If so, how can I do this? I looked through my computer but couldn't find how to do this.

Anybody help, please? D:

Edit:

specs, but it shouldn't be a hardware problem at all:
cpu: Intel Core i5 3570k
mobo: Gigabyte Z77X-D3H
ram: 8 gb
gpu: EVGA GeForce GTX 680
psu: 800w~

[Fuzzykins]

Post your specs please.

[Itheran]

cpu: Intel Core i5 3570k
cpu cooler: can't remember, but I do remember having bought separate fans.
mobo: Gigabyte Z77X-D3H
ram: can't remember, but 8gb
SSD: 256GB
HDD: 1TB
gpu: EVGA GeForce GTX 680
psu: 800W I believe

Pulled his setup from another thread. From that, i'am not seeing much of an issue as to why it's stuttering on you, It could be overheating issues (Maybe dust out your computer), It could be low dated graphic drivers, It could be bad cord or cord connections. Also you could try to run the game in windowed full-screen mode, that's usually a fix for many issues.

For specific's, a gtx 680 is a great card even now and should be able to run the advertised 4 monitors on a single card, though not for gaming with that many 2 should be a piece of cake for it, In short overkill for wow. MOBO is nice, i personally love ASUS and GIGABYTE as well. Core i5 3570k is a great CPU even only being 3rd gen, Some would say an i7 woulda been a better option but as a gamer, It's useless. And the 4rd gen i5 vs the i7 is almost so identical its pointless to spend the extra for the upgrade. Let's see, the power supply is, beleive it or not overkill for your setup, My system only uses 513 watt's of power and my system is as follows.
My new Computer as of 2014:
* Samsung 840 pro 128gig SSD for Main Drive
* WD Caviar Black 1tb for 2nd Drive
* Intel i5-4670k OC'd to 4gig CPU
* Coolermaster Hyper N520 CPU Cooler
* CM Storm Sirus 5.1 Headsets
* Logitech G600 MMO Mouse
* Tt Mechanical Brown Keyboard
* Corsair Vengence 8g DDR3 1600mhz Memory
* EVGA SuperNOVA Gold Certified 650W Modular Power Supply
* ASUS GTX 780Ti DirectCU II Grahpics card
* ASUS Maximus VI Hero MOBO
* AOC 29-inch IPS Q2963PM (21:9) Ultra WideLED Monitor
* Razer Goliathus 2014 Extended control edition mousepad, Wich is MASSIVE in size.

In short, Besides my suggestions up top, unless you give more details, theres not much anyone can do to assist you.

[Terahertz]

Heh, thanks for pulling up my specs Itheran. It shouldn't be a hardware problem at all since I was able to play shadows of mordor on my TV with ease (but then again, I only had my TV active).

Besides that, my main monitor is a 144hz one and my secondary is 60hz. I had already read that this may cause some conflict, but I've also read many people having no issues with it. I also tried windowed full screen mode. I always play in that mode anyways and it did not help me at all.

It's just a common issue many people have, but I can't find a fix for myself, which is why I went here. Maybe I should post on a different website that's more suited.