I have an i7-860. I currently have Hyper-threading disabled since games don't benefit (I turn it on when converting videos sometimes).
So my i7-860 without HT enabled is the same as your i5-750.
I have an overclocked GTX680 (Asus DCUII TOP version). Not even 10% of my games benefit from me overclocking the i7-860. When I overclock it to 3.6GHz only a few games benefit and the difference is very small.
"I think it would win, not at all the benches, but most : )"
Ok agreed. Just looked up a few more benchmarks.
Super Pi: An i5 750 at 4GHz scores 10.44, while a 3.1GHz i5 3450s scores 10.45. I'd argue that is a dead heat in that test.
WPrime 32M: i5 750 at 4GHz, 8.25sec, i5 3450 stock: 11.5 secs. This is a clear win for the OCed i5 750.
BTW, I have an i5 760 @ 3.4GHz (but at stock voltage) and am not trying to hype any CPU solution in particular.
You are asking if you can overclock your i5-750 even higher?
Not much likely. Why do you wish to?
1) it really won't matter for GAMES.
2) you'll be adding heat, thus noise, and increasing the possibility of killing your CPU.
Not only do I not recommend overclocking further, I recommend keeping your present overclock to no more han 3.8GHz.
So you STILL want to overclock?
1) The better the CPU cooler, the better the overclock (up to a point).
2) Frequency is increased until the CPU stress test or booting causes a CRASH
3) then the CPU VOLTAGE is slowly increased until things seem stable
4) then the CPU frequency is dropped down slighty (200MHz or so) to help with stability
5) double check that you did NOT overclock your RAM (usually you can just adjust the RAM's MULTIPLIER value, for example:
200MHz base clock x8 = 1600MHz
(if you overclocked the CPU and has a x12 base clock and 200MHz then your computer would try running RAM at 2400MHz and the RAM would cause your crash, not your CPU necessarily).
I don't recommend you overclock above 3.8GHz. There's little to no advantage to any games and the heat/noise level rises.