'09 MacPro's GT120 powerful enough for 2560x1440?

Thread title pretty much sums it up. According to everymac.com my machine (2.66 quad) can handle resolutions up to 2560x1600, but I wonder if it does so comfortably and seamlessly or whether there will be noticeable performance lag?

I am looking at an Asus PB278Q display, andnwould like to hear from others who use similar-sized displays at 2560x1440 with the GT120?

Thanks!