i5 3570k Or i7 2600

So ATM I have one of each and was wondering there would be any reason to put the 2600 in my high performance system (Maybe for hyperthreading?). Also would it be worth the cost of getting 2800mhz RAM over say 2133mhz RAM? Will there be a noticable difference?

the faster ram will not help much and is not really worth the price I say that 1866 is kind of the sweet spot right now for price to performace as its only a couple dollars more then 1333 or 1600.  For the cpu if you could get a high oc on the 2600 that will be better but other wise in games and other single threaded apps the 3570k will perform better assuming you have that oced too.

I can't seem to get the 2600 past 4.4Ghz woult it be worth switiching?

Nope, your PC is fine as it is, whatever performance increase that is offered with the 3570k over the 2500k is minscule and not worth upgrading. However, you could spend some money on a good CPU cooler to help get your OC on the 2500k furthur.

Ahh but I need to buy a new CPU anyway as this one is being borrowed from another computer. And I already have a custom loop so heat isn't an issue. I'm just not comfortable pushing the voltage any higher and more that 4.4 isn't stable. Guess I was just unlucky in the silicone lottery. 

I think I will probably go with the 3570k as I will probably be able to get a higher overclock which as you said will run programs that do not support more than four threads faster. Thankyou for the help. :)

Good idea mate ;).

Is it a 2600 or 2600K?

If you can already get it to 4.4ghz, then you should probably keep the i7. It should still outperform the 3570K, especially at that clock speed.

Keep in mind that higher clock speeds are not the only thing that determine how fast your CPU is, and most 3570K's can only get to around 4.6Ghz. A 4.4Ghz 2600 would easily outperform it.

It's a 2600 not a 2600k. So put the 3570k in the other computer?

If you will utilizes hyperthreading then yes swap out to the sandy otherwise stick with the ivy.

You will need a pretty good cpu to both heavily oc'd and run ram @2800mhz. Synthetic benchmarks, yes there will be an improvement, gaming, nothing to write home about.