How can I overclock my Intel Core 2 Duo E8400 higher on air?

[Centurion855]

Hey guys
I'm in need of a little assistance / advice on overclocking my Intel Core 2 Duo E8400.
I’m trying to overclock my E8400 from it’s stock speed of 3.00Ghz to as high as I can.
4.90Ghz (unstable) and 4.5Ghz fully stable are my main goals.

In order to do this I have of course replaced my Intel stock cooler with a good aftermarket cooler. I chose for the Scythe Mugen Max with an additional second fan. I also invested in faster 4GB DDR3-1333 CL9 Ram instead of my 4GB DDR2-800 CL5 sticks.

I already succeeded in reaching 4.80Ghz with a multiplier of x9 and FSB of 534Mhz at 1.72V.
CPU-Z Validation link: http://valid.x86.fr/pr1q41
I will soon try stabilizing the CPU at 4.5Ghz so it can pass a 24hour Prime95 stress test.

The problem is when I try to go higher than 4.80Ghz the “CPU host clock control” keeps resetting itself to disabled. Is there any way to prevent this from happening?
I already have advanced BIOS features like “CPU Enhanced halt”, “CPU themal monitor 2” and “CPU EIST function” set to disabled.

I also got this weird error when trying to boot at 4.85Ghz with my DDR3-1333 CL9 memory sticks:
Anyone know what it means? Here's a pic of it:

With my DDR2-800 CL5 memory sticks I can get my system to boot at 4.85Ghz at POST screen but it won't load into Windows. I think my RAM timings are set too aggressive.

Can someone give me some advice on which RAM timings I should fill in?
There are so many combinations I just don't know which ones to fill in lol.

Here's 2 pictures of my M.I.T. frequencies & voltages @ 4.85Ghz:
This is with the DDR2-800 CL5 sticks not the DDR3-1333 CL9 sticks.

MIT Frequencies & RAM timings:

MIT Voltages:

My full system specs:
CPU: Intel Core 2 Duo E8400 (3.00Ghz stock, E0 revision)
CPU Cooler: Scythe Mugen Max + optional second fan
GPU: Gigabyte GTX 560
RAM: Corsair XMS3 4GB (2x2GB) DDR3-1333 CL9 or Apacer 4GB (2x2GB) DDR2-800 CL5
Mobo: Gigabyte P35C-DS3R (latest F12 BIOS version)
HDD: Seagate Barracuda 7200.10 250GB 7200RPM
PSU: Cooler Master iGreen Power 600W
OS: Windows 10 Home 32-bit

Thanks to anyone who can help me out with this.

 

[aldan]

with these older systems the ram overclocks along with the cpu.check your ram frequency as some ram doesnt overclock well.you may have to manually set the frequency lower.

 

[Centurion855]

I already did that from the start, I set it to the lowest possible mutilplier which is 2.00. How else can I lower the ram frequency further?

 

[DeathRabit]

About DDR2 ~1000Mhz Timings try 9,9,9,28 for start and lower when working.
About DDR3 you mobo support it but most liekly not support OC well.

 

[Centurion855]

About DDR2 ~1000Mhz Timings try 9,9,9,28 for start and lower when working.
About DDR3 you mobo support it but most liekly not support OC well.

Ok i'll try those timings with my DDR2 memory.
I don't think it matters if my mobo supports DDR3 OC well because when i'm using a memory mutiplier of 2.00 I am staying below the rated speed of 1333Mhz, right?
For example: FSB at 530 * 9 (4.77Ghz) with memory mutiplier 2.00 = DDR3 memory running @ 1060Mhz which is still under 1333Mhz so it's not OC'd.

 

[DeathRabit]

With DDR3 set Voltages on AUTO 😉

 

[Centurion855]

I can't put it on auto only on normal or +0.1-0.7V but I assume that is what you meant.

 

[Centurion855]

About DDR2 ~1000Mhz Timings try 9,9,9,28 for start and lower when working.
About DDR3 you mobo support it but most liekly not support OC well.

I can't put my timings for my DDR2 memory at 9-9-9-28 because the highest my CAS# Latency can go is 6.
I tried 6-6-6-18 with memory mutiplier 2.00 at 2.5V and then it booted at 4.75Ghz and loaded into windows but then after a few seconds it crashed and gave me this eror: WHEA_UNCORRECTABLE_ERROR.
Another error I got when I rebooted later on was: MEMORY_MANAGEMENT.

Using the program "SetFSB" I booted into windows and then increased the FSB manually in windows from 4.68Ghz to 4.90Ghz!!
This was when I booted with a Vcore of 1.8V. I hope I can manage do this again and get it to validate at 5Ghz.

 

[Centurion855]

New problem: When I try to validate my E8400 with CPU-Z at 4.94Ghz or a little higher CPU-Z crashes right after when I click the "save manual validation file" button 🙁 When I try the normal "submit" button the same thing happens.

 

[DeathRabit]

To much memory error on this high clocks. Programs will,not work properly.

 

[Centurion855]

Ye it's unstable but that doesn't really matter since i'm only after the highest CPU-Z validation possible. I only would like to get it stable at 4.4Ghz.

But now i've bumped into a new problem:
When I try to validate my E8400 with CPU-Z at 4.94Ghz or a little higher CPU-Z crashes right after when I click the "save manual validation file" button 🙁 When I try the normal "submit" button the same thing happens. I have also tried running CPU-Z in 'extreme OC mode" but then it still crashes...

 

[aldan]

its not likely you are going to get it anywhere near stable at 4.4ghz.up the frequency a little at a time and check it with a program like occt after every adjustment.also check the actual ram frequency as well.

 

[4Ryan6]

Any time you switch between the DDR2 and DDR3 memory always do a hard clearing of the CMOS settings, many think the motherboard auto recognizes and in most cases it does, but may not show you all the BIOS settings the different memory modules can use, so to be safe do a hard clearing of the CMOS settings, usually accomplished with the motherboard jumper.

Not clearing the CMOS settings could account for the error code you got?

Your motherboard manual is very frustrating because it did not show any of your available BIOS features, at least the one I downloaded from Gigabyte did not, without knowing the features or setting you have available to you, it is rather difficult to help much other than trying to further what you've already tested.

I have to admit I am not a Gigabyte motherboard user so my familiarity with it is limited to what I can discover from you?

I did however for my own qualifications have a Q9550 I overclocked to 4ghz using an ASUS Striker II Extreme running 4Gb of 2,000mhz memory using a Xigmatek S1283 HDT air cooler running 110cfm cooling fans.

So far it seems you're after the highest CPU-Z validation you can possibly achieve and then stabilize somewhere around 4.4ghz?

Is that your goal?

If you have any limitations it will be that motherboard you have and not because of the Gigabyte brand but because it could run either DDR2 or DDR3 memory, meaning it was not fully dedicated to either DDR2 or DDR3, and was more of a buying convenience feature, than an overclocking featured motherboard, compared to some of the dedicated overclocking motherboards of it's day.

However you've made great progress so far so keep at it!

Edit: I took a good look at the Scythe Mugen Max and I have to say I am impressed with it!
It actually outperformed the Noctua NH-D14 under an overclocked test load, and it is obviously a passive cooler from the looks of it, meaning you can increase it's cooling capability by going to higher CFM cooling fans, say in the 120mm 110cfm range!
It comes with a 140mm cooling fan but the fan has 120mm mounting tabs, FYI.
I also love it's heat pipe back set forming allowing clearance for the system memory modules, well done Scythe!
Good Choice on your part!

You can learn a lot here, to see how realistic your goals are, compared to some of the best overclocks achieved with the E8400.

 

[Centurion855]

When I switched between DDR2 and DDR3 memory I always did a CMOS clearing by touching the 2 jumper pins on the motherboard with a screwdriver.

And yes my goal is the highest CPU-Z validation possible and 4.4Ghz fully stable.
So far i've managed to reach 4.91Ghz (http://valid.x86.fr/s3w29l unstable ofc) and 4.00Ghz stable (24hours of Prime95 blend).
I would really love to reach the 5Ghz number, but when I try to boot at 4.68Ghz and increase the FSB in windows with the program "setFSB" I'm able to reach 4.95Ghz but when I try to validate it using CPU-Z it crashes as soon as I click the "submit" or "save manual validation file" button. Very frustrating...

And yeah the motherboard isn't great, that's why I would like to buy a second hand Gigabyte EP45-UD3P. But I can't find one for a good price 🙁

I'm happy with the Scythe Mugen Max, I first bought a CM Hyper TX3 EVO but that wasn't much of an improvement over the intel stock cooler.

When I look at that list I see about 5 people who managed to stabilize (assuming those are all stable OC's) their E8400 at around 4.4Ghz. Given that I have such a good cooler I think it should be possible.