i have a 2500k and i have only over clocked it to 4.0 at the moment. everything is just right. I dont see the point of over clocking it any higher than 4.2. unless you are playing wickedly CPU intensive games...SSD sounds like a good move to me.
Depends on what youre using your rig for. If youre using it for gaming and are running at a 1920x1080 or better, I doubt youd see any difference at all.
I had a Phenom II 940 X4 before I went to a 2500k now overclocked to 4.2 and if you are concerned about gaming I have noted little change. (Using a 5850) The only difference that I can really say I have noticed is it installed Windows 7 faster So with your i5 750 you should be plenty good.
i went from an i5 @3.6 to a 2500k @4.8 - and i can tell a difference. is it as drastic as going from a p4-3.0ghz to the i5, no - but it's worth it if you sell your old mobo/cpu/ram.
You went from an [email protected] GHz to a [email protected] GHz? Wouldn't the performance increase be because of the 1.2 GHz increase in speed you got from the upgrade. Ban916, you would probably get more gain by moving to a SSD drive than upgrading to a new cpu.
I went from a Q9650 at 4.2ghz to a 2500k at 5.0ghz and didnt notice much of a difference at all other than in BC2. Considering you already have an i5 id go for the SSD and hold off til Ivy Bridge.
OC'ing it probably puts you equal to, if not faster than a stock 2500k. Of course you can OC the 2500k but having a SSD will have a more noticeable impact IMO.
I would definitely invest in an SSD first and then maybe upgrade your RAM to 8 gigs before I would worry about another CPU upgrade until there's a more noticeble difference in what your upgrading to.
Considering the fact that Sandy Bridge, on average, is roughly 10-12% faster per clock than Nehalem and you`re already running your i5 750 at 4,2GHz, I`d say it`s not worth upgrading whatsoever. Get the SSD now and hold off until Ivy Bridge is released.