How can I overclock my Intel E6750 higher?

[Centurion855]

Hey guys
I'm wondering how I can overclock my Intel Core 2 Duo E6750 higher than i have so far.
I would like to get it up to 4Ghz. The highest I could reach so far was 3.70Ghz. If i set the FSB higher than 475x8 it reverts the settings and goes back to 2.66Ghz (333x8).

Of course I have invested in my system in order to do this:
- I replaced the intel stock cooler with a Cooler Matser Hyper TX3 Evo.
- I bought faster 4GB DDR3-1333Mhz CL 9 RAM instead of the 4GB DDR2-800Mhz CL5.

Here's a CPU-Z validation link of my highest overclock so far of 3.72Ghz: http://valid.x86.fr/36wsgi

M.I.T. Frequencies:

M.I.T. Voltages:

At 3.60Ghz it was stable in Prime95 for 8+ hours without an error.

What settings do I need to adjust to reach 4Ghz? When I increase FSB higher than 475x8 it goes back to 2.66Ghz, how can I prevent this from happening?
I already have advanced BIOS features like Thermal Monitoring and Enhanced Halt State set to [disabled]. As you can see here:

PS: As you can see here there are alot of people who managed to OC their E6750 higher than 3.70Ghz so it is perfectly possible: http://us.hardware.info/productinfo/2142/intel-core-2-duo-e6750/overclock

My PC specs:
CPU: Intel Core 2 Duo E7650 (2.66Ghz stock speed)
GPU: XFX Geforce 8500 GT
RAM: Corsair XMS3 4GB (2x2GB) DDR3-1333 CL 9
Mobo: Gigabyte P35C-DS3R
HDD 1: Seagate Barracuda 7200.10 250GB 7200RPM
PSU: Aopen Z400-08FC 400W
OS: Windows 10 Home 32-bit

Any help would be much appreciated

 

[faalin]

have you looked to see if there is a newer bios version for your board, or are you on the latest one?


I had an asus rampage 3 extreme board that would not let me overclock the ram more them 1800mhz till i did a bios update.

 

[Saberus]

While others might have done it, you might have lost at the silicon lottery. 3.7 is already a lot out of that old chip. Only thing I can think of is maybe going to a lower multiplier might net you the stability to crank the FSB a bit more, but at 6x you'd need a FSB of 667 to crack 4GHz.

 

[Centurion855]

have you looked to see if there is a newer bios version for your board, or are you on the latest one?


I had an asus rampage 3 extreme board that would not let me overclock the ram more them 1800mhz till i did a bios update.

Yes I have already updated my BIOS to the latest version which is F12.

 

[Centurion855]

While others might have done it, you might have lost at the silicon lottery. 3.7 is already a lot out of that old chip. Only thing I can think of is maybe going to a lower multiplier might net you the stability to crank the FSB a bit more, but at 6x you'd need a FSB of 667 to crack 4GHz.

Ye I know 3.70Ghz is already alot but after investing in faster ram + a better cooler I would really like to reach 4Ghz. I'll try setting the cpu multiplier to 6x and the increasing the FSB slowly in steps to 667 and see what it does.

 

[Centurion855]

Update: Dropping the multiplier to 6x and then increasing the FSB up to 667 didn't work. It always goed back to 2.66Ghz. Anyone any ideas on how to prevent this from happening? Please look my screenshots in the OP for more info.

 

[Saberus]

Maybe the overvoltage protections are kicking in. the CPU is already running at 1.6v which is much higher than the 4.004GHz run, which had a 1.425v The highest voltage I see in the top ranks of your link is the watercooled 4GHz run with a 1.8v. That guy's just burning out his chip for a score.

I think the only way you're going to push 4GHz out of this thing is to burn it out. Not all chips of the same model are going to be able to pull off the same overclocks.

 

[Centurion855]

I just bought a way better cooler today (+ optional second fan): The Sycthe Mugen Max which is supposed to be even better than the CM 212 EVO & the Sycthe Mugen 4.
I'm going to let Prime95 run now for 15+ minutes at stock speed with stock voltages and see which temperatures I get now.

Here's a pic of it:

 

[Centurion855]

I isolated the problem:
What happens is when I go over 3.80Ghz (475x8) the "CPU Host Clock Control" resets itself to [disabled].
I have advanced BIOS feautues like "CPU enhanced halt", "CPU thermal monitor 2" & "CPU EIST" already set to [disabled].

Here's a picture:
http://www.overclock.net/t/1570163/lightbox/post/24315061/id/2556932

Does anyone know how to prevent this from happening? I already updated to the latest BIOS version and I checked all the hidden BIOS options. =(