OC'ing an E8400

Having not long had an E8400 in my PC, and seeing the remarkable overclocking results others have reported, it seemed a shame to leave mine at just 3ghz... I am aiming for 3.6ghz.

My System:
E8400 3Ghz
2x 1Gb OCZ DDR2-800 PC2-6400 Platinum
Akasa AK-965
550W PSU
(Powercolor HD4870PCS+ very soon)

MIB Intelligent Tweaker at the moment:

Robust Graphics Booster [Auto]
CPU Clock Ratio [9x]
x Fine CPU Clock Ratio x0.0 (greyed out)
CPU Frequency 3.00GHz (333x9) (greyed out)
CPU Host Clock Control [Disabled]
x CPU Host Frequency (Mhz) [200] (greyed out)
PCI Express Frequency (Mhz) [Auto]
C.I.A 2 [Disabled]
Performance Enhance [Standard]
System Memory Multiplyer (SPD) [Auto]
Memory Frequency (Mhz) 800 800 (greyed out)
****System Voltage Optimized****
System Voltage Control [Auto]
x DDR2 Overvoltage Control Normal (greyed out)
x PCI-E Overvoltage Control Normal (greyed out)
x FSB Overvoltage Control Normal (greyed out)
x (G) MCH Overvoltage Control Normal (greyed out)
x CPU Voltage Control Normal (greyed out)
x Normal CPU Vcore Normal (greyed out)

When CPU Host Clock Control is set to Enabled, 2 of the above settings are changed:
CPU Frequency 1.80Ghz (200x9) (now not greyed out)
Memory Frequency (Mhz) 800 480 (still greyed out)
(I assume the reason the CPU frequency goes down is because the CPU Host Frequency is set at 200 at default on manual, although I am not sure why the memory frequency goes down to 480)

After extensively searching for an overclocking guide that included my MB I have come up short. I can only assume that the method is the same for many gigabyte MB's. These are the instructions I have found:
Manually decrease system memory multiplyer to minimum (usually 2.0).
Manually set PCI Express Frequency to 100.
Slowly increase CPU Host Frequency (FSB) by increments of 10 until I reach 400
Is this correct? Is there any chance of my CPU/graphics card getting messed up permanently if I attempt this?
18 answers Last reply
More about e8400
  1. Hey fellow first timer.

    As far as stepping it up by 10 that sounds about right, once you can't boot then move it back a few ~5 and try again. Then you need to stress the CPU (Prime 95 is good for this) to make sure it stays stable for a few hours (# of hours depends on person...I personally am aiming at 12-hours).

    You shouldn't be able to mess up your CPU or Graphics card unless you start messing with voltages.

    Someone else can correct me if I am wrong.
  2. so all the instructions i wrote above are correct? about memory multiplyer at low and pci express and 100? If I push the CPU too far will it allow me to get back into bios? Its just the last time I tried a minor OC of 10 I think I forgot to change the system memory and my x1950 artifacted everywhere, I still don't know if it will work again, or why it happened...
    Also, if the voltages are set on auto, would they increase to match my other settings, thereby putting my components at risk?
  3. I believe with a minor OC you should not have to change voltages...I would just hard code them instead of doing auto. As far as getting back in to the bios you may need to reset your Bios (Consult motherboard manual). I have a crash free bios so if mine won't boot after 3 tries it restores default settings.

    I don't know why you graphics card would artifact...I will leave that for someone a little more advanced than me. Also auto seems to take the voltages a little higher than they need to be...so when you increase the FSB high enough you may need to raise the voltages...check out the specs on your proc and see what it can handle.
  4. I was afraid you would say that. Most guides make it seem so easy to do this, but it is far from in my opinion. I don't know enough about overclocking to mess around with voltages, plus I don't know my voltages, and I don't want to risk ruining my E8400 so soon. I reckon I shall give up for the time being, and hopefully meet someone who can do it for me.
  5. Can anyone recommend a Motherboard that OC's better? That doesn't require me to mess around with voltages?
    I can report that my x1950pro is permanently screwed, seeing as it is still artifacting with my standard BIOS settings
  6. I have an asus pn5-d and my e8400 is oc to 4 ghz. I bumped my cpu volts to 1.32 and north bridge to 1.36. I could use the overclock option build into the bios but it will only max to 20 percent. It has an auto overclock setting you might like. lets say your fsb is 1333 stock bump it up to 1500 or so and see if you pc will post. If it does push it to 1550 and try it. It will get to a point to where you will need more volts on the cpu and nb. the main thing I would worry about is temps but don't go crazy on your volts cause it adds to the heat also.. I would guess your board would oc just the same but maybe I am wrong. Good luck
  7. I forgot to say mine is water cooled so you would 4ghz mark on air..
  8. Thanks for the input christop, but I aint got a clue what you are on about; I reckon I got the gist of it though.
    Seeing as messing around with voltages is necessary to overclock, I don't have the nerve to do it. In fact I don't even have the nerve to try the gigabyte easytuner. Also, I don't even know what a northbridge is, let alone how to change the voltage of it. I don't see any mention of northbridge on my Intelligent Tweaker, also no-one on the internet has said what voltage the E8400 runs at standard, so I wouldn't even know which voltage to begin with with the CPU, or how many increments increase, or which to change first; the FSB or voltage, or what to do if I can't get the computer back up and running after a failed attempt (I tried looking up the technique mentioned above, couldn't find anything). None of these questions seem to be getting answered, as far as I can tell, and until they are answered at a level I can understand, I don't think I shall be OC'ing any time soon. To me even the "beginners guides" dotted around the net aren't clear enough.
  9. Hey play around with the easy tune. It WILL NOT BREAK ANYTHING. To tell you the truth I can't tell a thing from mine running at 3.0 to 4 ghz maybe I am wrong..
  10. Everyone says its not worth using software to OC, but rather do it via BIOS. Seeing as I am an idiot n00b who doesn't know what he's doing, and I don't have enough money to replace anything that screws up, I shall end this here by saying thanks for trying to help, but I withdraw my questions.
  11. I just tried easytune on easy mode, +1mhz, and it totally froze my computer, now upon restart my bus speed has lowered to 329 from 333, how to I change it back?
  12. Never mind, its been rectified... stupid software.
  13. gigabyte boards are usually good for overclocking, though i've never used a P31 board before. i overclocked mine on a ga-ep45-ud3p to 3.6ghz on stock voltages and stock cooler, though i now have it at 4.0ghz @ 1.32v w/ a 212+ heatsink. there's no need to be afraid of OC'ing through BIOS. just make sure you don't push cpu voltage above ~1.36.

    then again, the overclockability of your cpu often depends on your particular chip. luck of the draw sometimes :/
  14. Running an e8400@4ghz myself on a Gigabyte GA-EP45-UD3LR, with these bios settings:

    1.960v on the memory(Corsair XMS2DHX 4gb)
    445mhz bus
    100mhz PCI-E
    9x multiplier(standard, but my board had it put a 8.5 at stock)
    Running stable at 4ghz for more than a week now, on air. Max temps on the cores is around 63c under ORTHOS. Using a cheap Zalman cooler.

    Also, http://www.legionhardware.com/document.php?id=717&p=3
  15. That OC guide is where I got the instructions listed above. It doesn't mention when OC'ing to 3.6 that I need to change voltages. What is the voltage of an E8400 when not overclocked. On my CPUIDHWM it says for cpu vcore:
    min: 1.06V
    Max: 1.25V

    Should I set the vcore in my BIOS tweaker manually to 1.25V to begin with then? Or less? Then raise FSB slowly FSB to 400? Do I set the memory multiplyer and pci-e frequency BEFORE I change the voltage and FSB?
  16. After reading more of the OC guide, they state that at 3.6ghz the voltage was set at 1.225V. Should I set my vcore voltage to that number then? Do I need to change voltage on the RAM? If so, up or down?
  17. I just found another guide to OC'ing an E8400. Does anyone else recommend I follow these instructions to the letter?
  18. At 3.6ghz, you could start your voltage lower than 1.225, but it might not be stable. The CPU is more than capable of running at 1.225v, and you will not damage it at this voltage.
    My advice is that you start out at 400mhz fsb, 1.225v on the core and test your system in ORTHOS while monitoring your temps(65 cpu/ 70 core is safe). If the system crashes(which is shouldn't at 3.6) try lowering the latency of your ram. If it overheats, well, get a new cooler. The E8400 shouldn't overheat at 400mhz fsb.
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