How much of a difference between GeForce GTX460 768MB and 1024MB?

I want to buy a new graphics card, and I heard that the GTX460 has a great performance for the price. But there are 2 models, a 768MB one and a 1024MB one. Is it worth it to spend more for the 1024MB one? How much of a difference does the extra memory make?|||The difference is not just the amount of memory. The 1GB version cards have a 256-bit memory interface, and the 768MB version cards have a 192-bit memory interface.



The performance advantage of the 1GB version card is in the area of 6%-7% overall.



http://www.tomshardware.com/charts/2010-…



If I were trying to build a gaming system on a budget, I would save money using the 768MB version, spend a tad more on the CPU, and then pocket the difference.



This is a straight-up reference design, for only $150, Sparkle SXX460768D5UNM (GeForce GTX 460 768MB),



http://www.tigerdirect.com/applications/…