I've decided that for my first build 8GB of RAM (2 x 4GB) will probably be more than enough for gaming. Now I need to know how much of a real-world effect CAS latency will have on my performance. By "real-world" I mean that obviously DDR3 1600 RAM running at 7-7-7-24 is faster than the same RAM running at 9-9-9-24. But, will I notice the difference in FPS or system responsiveness? If not I'll save a decent amount of money and go with the CAS 9. Here are the three sets of RAM I'm looking at. Thanks for any advice!
Between the absolute fastest RAM and the absolute slowest RAM, there is only a 8-10% difference in most real-world workloads. If you put the $40 difference in a better GPU, you can get 30-50% higher frame rates.
So RAM speed is not really worth worrying about that much unless budget is a non-issue or you have a specific application in mind that absolutely requires it.