Today we're going to overclock your Core i5 750 or 760 processor, this guide should get you 3ghz without any issue at all, and probably more. It leaves the ram pretty much alone, and doesn't tune things to any great extent, it won't get you 4ghz but it's something to play with, and it may well get you close with small modifications (namely, for BCLK over 160mhz, set the ram speed another notch lower).

Please note that overclocking can cause issues, we're going to test for them, but you can still get unexpected results later on.
You may have to open your case and move the jumper on the CLR_CMOS pins to reset the bios to stock everything.  I doubt it, but it's possible.

Warning: Overclocking can damage your hardware. Funky Kit is NOT responsible for any damages as a result of overclocking. Any overclocking is done at your own RISK!

Step by Step Guide ...

1) Find and download "CPUz", "Coretemp", and "IntelBurnTest".

2) Run CPUz, this is how you'll know how fast the cpu is going, as well as ram and such.

3) Run Coretemp, this is how you'll know how hot things are, you want under 80*c with IntelBurnTest running.

4) First actual OCing step, find the "VID" box in coretemp, and write that number down.  Now open CPUz and click the "SPD" tab and write down how much voltage the ram wants (at it's fastest).

5) Reboot and enter BIOS, find the OCing page (gigabyte is usually pretty obvious about it).   Please note that all the following settings will be set to AUTO when you find them.

6) On that page, find "Vcore", or "Core Voltage", or "CPU Voltage", I don't remember what gigabyte calls it.  Set it to the VID you got from coretemp.  Find "DRAM Voltage" or "Memory voltage" and set it to the voltage you got from the CPUz SPD tab.

7) Also on that page, will be something labeled "VTT", or "QPI/DRAM", or possibly "DRAM BUS VOLTAGE".  Set it to 1.25 volts.

8) Find the DRAM Speed setting, or Memory Speed, or something along those lines.  Set it to "1333". (Please note:  This step assumes you have 1600 memory.  If you have 1333 memory set it to "1066", if you have 1066 memory, set it to "800)

9) Find the "BCLK" or "Base Clock" setting, 133 is totally stock.  This setting does the actual overclocking.  The CPU speed is BCLK times the CPU Multiplier.  A 750 has a multi of 20x, so at stock it is 133mhz X 20 = 2660mhz, or 2.6ghz.

10) We're aiming for 3ghz right now, so 150 BCLK is our goal.  For starters, set BCLK to 140mhz.

11) Save settings, exit the bios, and load windows.  Once windows loads, open CPUz and check the BCLK box, it'll say 140.

12) Open up CoreTemp.

13) Odds are CPUz will say your cpu is running at 1260mhz on a 9x multi, this is OK, expected, and good really.  Run IntelBurnTest and watch the CPU speed jump up to 2800.  Let IBT (Intel Burn Test) run until it completes, it'll pop a window up saying "We made it!"  While IBT is running, check the temps in CoreTemp.

14) If IBT is happy, go back to bios and set BCLK to 150, save-exit, load windows, open coretemp, run cpuz, and run IBT again.  You should be at 3ghz, have nice cool temps, and get through IBT.

15) You can continue doing this (raise BCLK, test, raise BCLK, test, etc.) until IBT gives you an error message, or windows fails to load, or the computer fails to POST (give a screen display) at all.  At that point you need to add some VCore and/or some VTT (don't go over 1.37vcore or vtt), or back BCLK down to the last settings that worked.

16) Once you're happy with the speed it is going, open IBT again (getting tired of IBT yet?), use the dropdown box at the top to select "maximum" stress level, and enter "10" into the "Times to run" box.  Hit start and go do something else, this'll take a bit.  If it completes happily you're all set, enjoy your new speed!

You can visit the forums for a more detail discussion here ... http://www.funkykit.com/forums/index.php/topic,3246.msg4776.html

Disclaimer ... Warning: Overclocking can damage your hardware. Funky Kit is NOT responsible for any damages as a result of overclocking. Any overclocking is done at your own RISK!