Hi there, In the very near future I plan on giving my PC a bit of an upgrade as I'm still on LGA775. At the moment I'm just going for a new motherboard, CPU and RAM but I'll be getting a new graphics card not too long after that. I live in New Zealand so the options are a little constricted but so far I've decided to go with:
For the most part I'll be using this for gaming but also a bit of audio recording and editing. I realize that 16GB of RAM is overkill for the vast majority of applications but it's so cheap that really, why not? Also, is there any point in going with the 3570K over the 2500K? There's only a $30NZD difference between the two but for added heat and tiny performance increase is it worth it. I would rather buy a new gen CPU instead of going with old stuff but performance is the biggest decider. I will be overclocking pretty much as far as I can go with a Hyper 212+ cooler.
Because it provides literally no benefit whatsoever. It's not a small benefit, it's literally zero. Nada. Nothing. You're paying extra for absolutely nothing. It's pretty rare that people use more than 4GB or so. 8GB is already at the level of "it's cheap, so go ahead and get a bunch.' There is just no reason to get 16GB unless you're using one of the handful of programs that can actually make use of that much memory. These programs are pretty much exclusively in the video/image editing category.
You could take the difference in price and put it into a nicer air cooler like the NH-D14 and actually get a performance boost out of it. Or a better video card, or bigger hard drive, or SSD, or any one of a number of things that will actually have an impact on the performance of your computer.
As far as the 3570k vs 2500k, I'd say go with the 2500k unless you get a big air cooler like the Silver Arrow or NH-D14. The Hyper 212 is going to have a lot of trouble keeping up with the heat the 3570k produces when overclocked.
With the 212, you could expect about 4.4-4.5 GHz out of the 3570k, and it's going to be running really, really hot to do it. The same cooler on a 2500k will do 5.0 GHz+ without much trouble, and maybe even higher if you get lucky with your chip. The massive lead in clock speed is going to make the 2500k every bit as fast as the 3570k, if not faster.
The Corsair memory has better timings, and will thus be about 10% faster. It will probably overclock better as well, because you can loosen the timings and crank up the speed.
My DDR3-1333 runs at CAS 7 by default, but it will do DDR3-1600 if I loosen the timings to 9. The difference in performance is small (~4%), but I benched it thoroughly and it does perform a bit better at the higher speed with worse timings. Was able to get it even higher at CAS 9, but I was getting errors and had to back off a bit on the overclock. It's not the highest quality kit.