Want me to show you benchmarks where the 1090T surpasses the I5-2500K??? talking of single threaded benchmarks(games) and multithreaded too. I saw bunch of them where they were pinning down the Bulldozer vs the 2600K,2500K and the 1100T(my bad not the 1090T...same $hit BTW)
I'm kind of curious what you are referring to, actually.
All my research suggests that the 2500K outclasses the X6 Phenom II's in pretty much every regard, except a very few encoding and rendering apps where the X6 can fully take advantage of all its cores, but even then the 2500K takes most of these too.
Stock to stock, the 2500K will dominate the 1100T or 1090T in the vast majority of applications.
You can make up for this - to some extent - by overclocking the Phenom II to about 4ghz (some have hit 4.2, but 4 is the most common.) but even when you do this, it doesn't bring the single core performance up to par with a stock clocked 2500K.
And if you are going to overclock, the 2500K has been known to hit 4.8Ghz on air. At that speed, the Phenom II would need to run at almost 7Ghz in order to keep up.
It's quite simply very lopsided right now. AMD, even after the Bulldozer launch is nowhere near competing with Intel, unfortunately.
The reason you don't see this in most games, is because most games are not very CPU intensive, and as such are limited by the GPU, not the CPU. There are some notable exceptions to this. RO2 as we all know is one. StarCraft 2 is even more so.