I was going by the overall increase and I dont consider 30-40% or even 50% overall to be much of an upgrade from a 5 year old card. after 5 years he should be looking at getting way more than double the overall performance imo.
not exactly, if 5 years ago he was buying more expensive hardware, and the CPU was a lot better for the time.
http://static.techspot.com/articles-info/458/bench/1920_High.png
just as a reference how the 4890 looked on BF3...
in games like this I would expect the 260x to perform over 2.5x