I found that going from an x5650 to a 2700x was a pretty big uplift in gaming performance at 1080p, a lot more than I'd anticipated. My lows are nothing like now, where on pube-g I'd see the odd dip into the 60-80fps range (which doesn't sound bad, but on a 144hz screen when it's usually averaging 140-160fps it's really noticeable) with some extreme instances of hitting into the mid 40's. Since upgrading average fps is 180-200+ and not seen it go below 140fps. If you're gaming at 1440p then it might not be as much of an issue, but I think average and 1% lows will improve a load, but I think the frame times and consistency will also be where a gaming experience can be soured.