I thought you linked to http://www.iloveegg.co.uk/
Let's hope you have pci-e2.0...
That wouldn't matter because all PCIe 2.0 graphics cards are backwards compatible with older versions of PCIe.
Can it fit in your case, and can your power supply handle it?
Newer cards like the GTS250 get a slight bottleneck.
I'm pretty sure it will. My computer is quite powerful except for the current graphics card.