My graphics card had performed bad and after upgrading I feel it may have been because I had it connected to a 4x pcie slot

[fatsoh]

does it make a difference which slot i put it in? 16x or 4x?

 

[blacksheep123]

yes a big difference... 16x is four times faster than a 4x slot

 

[D-Saad Malik]

http://www.techpowerup.com/reviews/Intel/Ivy_Bridge_PCI-Express_Scaling/23.html