E8400 + IP35 Pro OC woes...

I'm having a hard time with the OC on my E8400. Everyone says I should be able to hit 4.0 w/ it on air but I can hardly get 3.8 stable at 1.37/1.38 core voltage.

Could you all help me out possibly? Maybe I have a bum chip, but I think it may have something to do with the other options in my bios. I have version 17 for this mobo, but I'm not sure how much to cut/bump all the other voltage settings. Also I'm not sure what I want to have enabled/disabled for some of the settings, like the major ones that will make a difference.

If possibly I could get some help I would be greatly appreciative. Just let me know what other numbers/values you'd want to know from bios and I'll check them and repost, thanks in advance.

Here is a SS of some CPU-Z's.

What is your PLL/VTT/and NB voltages set at?

E8400. Everyone says I should be able to hit 4.0 w/ it on air

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Everyone would be wrong, alot of E8400 Rev C0 will not do 4Ghz stable on air.

3.8 maybe as good as it gets with that chip/cooling.

It is a crapshoot with the C0. Thing is though, he has plenty more vcore to go to get there. My C0 a year ago would hit 4Ghz @ 1.4 and 4.3Ghz at 1.5.

Well at least I can see that it may just be the CO stepping. I'll get back to you on the voltages in a bit.

NB should be plenty for those speeds. Thats what Im at with a quad!

Raise the VTT (FSB termination) a bit and see if that helps.

that would be CPU VTT in the bios i imagine, when you say a "bit" is that like .05ish? or?

If I indeed got a "bum" C0 stepping I wouldn't be surprised. At least I know that I'm not the only one who had problems and that it's happened to others w/ this stepping.

Yeah, try .1 then back it down as needed.

I overclock a bit different than a lot of people. I dont creep up the voltages, I raise them up, get to my goal THEN back them down.

What about these values under "CPU Feature" in my BIOS. I'll list what they are, and what I have them set to, I think I have these right.

Thermal Control- Enabled
Limit CPUID MaxVal- Disabled
C1E Function- Disabled
Execute Disable bit- Enabled
EISF Function- Disabled

I uped VTT by .7 before I read your latest post, going to try this and see what happens.


~edit: TY for helping a noob btw.

Also what value for Core Voltage should I really be watching, under load or not? Thanks.

I hope you meant .07. LOL

Keep both voltages in mind really. BIOS and load.

Lol ya i did mean .07 =P

At 1.36 Vcore under Orthos load atm @ 3852 MHz... I'll try this for a bit, and go from there. Any thoughts on the other values I mentioned?

Thermal Control is just for a safety measure if it gets to XX temps, it will shut down.

I turn off the execute disable bit, but I dont think it matters.

nvm, i see the bios rev... have you tried using bios 16? since im having no problems with in on 45nm dual core i would suggest that one first. though some others have reported good ocing on bios 17. i just have found for ocing bios 14 for 65nm cpus dual or quad, bios 16 for 45nm duals, bios 17 for quads. well that was just from reading the abit forums a long time ago...

Did you attempt to run Small FFT Prime95 rather than blend to test for stability?

422 bus is OC'ing your ram by 44mhz. Its *possible* that could be causing the instability although you are running 5-5-5-15 timings which should help it out.

Evilsizer said:

nvm, i see the bios rev... have you tried using bios 16? since im having no problems with in on 45nm dual core i would suggest that one first. though some others have reported good ocing on bios 17. i just have found for ocing bios 14 for 65nm cpus dual or quad, bios 16 for 45nm duals, bios 17 for quads. well that was just from reading the abit forums a long time ago...

Click to expand...

Thanks I'll give that a shot.

doz said:

Did you attempt to run Small FFT Prime95 rather than blend to test for stability?

422 bus is OC'ing your ram by 44mhz. Its *possible* that could be causing the instability although you are running 5-5-5-15 timings which should help it out.

Click to expand...

I dropped the Multi to 8x and uped the FSB to where I would need to be at 9x multi to be at 4ghz ( 445mhz) and had no problems. I even went so far as to drop to 7x and push 500mhz and had no issues then. So if I'm not mistaken that's a way to proof test my ram for its speed capabilities?

Maybe I'm off base here though.



I tried to let it run Orthos overnight at 3.8 and woke up to a crashed machine. I'm beginning to think I just have a bum chip, but I'm still holding out hope that it could be just because I'm a noob.


~edit: I have a 2x 2gb set of G. Skill DDR2 1066 (PC2 8500) on it's way to see if that might help a bit. Decided to grab those and a copy of 64 bit Vista cause I was bored.

Meh, still not able to get an overnight run of Orthos at the above voltages at 3.8GHz. Think I'll pump the voltage a bit more, I know it's not recommended to go above the point I already am at, but I might as well try to see if it can be done. =P Maybe I'll get lucky and get an E0 if I need a replacement. Is there any way to guarantee yourself to get an E0 when ordering online by the way? I know I can walk into a brick and mortar and look at the box, but I don't really have any good parts stores near my home that can compete w/ online pricing.

Didn't have time to flash over to the v.16 bios last night, will try that when I'm off work today too.

well im assuming your sticking with the stock 9x multi on the E8400. if that is the cause then the problem is more then likly ram related. as it is DDR2-800 cas5 2x2gig kit wich means that it could be the low speed ic's D9HNL. i have a 1gig stick (single sided) with D9HNL's mine topped out at DDR2-900 [email protected]. at 3.8ghz by 9x your only running 422fsb, you should have a bit more leway. what kind of voltage you putting into the ram, is it spec or higher, what is the spec voltage for it?

Here are the specs copied from the Newegg page:
Capacity 4GB (2 x 2GB)
Speed DDR2 800 (PC2 6400)
Cas Latency 4
Timing 4-4-4-12
Voltage 2.2V


I'm currently putting 2.28 into them according to Everest. If you look a couple posts up, I was able to drop the multi to 7x and push the FSB to 500 and played around for a bit before I changed my multi back. Though I never did try and stress it, I'd say the fact that it could boot at 500, running at 9x 422 the memory shouldn't be an issue. Like I said above I do have some new G.Skill PC2 8500 on the way to really put the issue of memory to bed. I'm hoping that it's just that easy, but I just don't think that's it when I look at where I was able to go with the FSB on those sticks.

I'll also play around with just stressing the CPU as mentioned above. I didn't really have any time to mess with settings last night so I'm hoping to get to play w/ it today when I'm off work. I also plan on re-reading the sticky about OC'ing these as to get a better idea of the steps I need to take and what to really keep track of. Going through it again a few mins ago I realized that when you get to the section where you follow the author's attempts and what changes he made to get stability there is some good general info.

I want to thank everyone for their help but this goose is cooked. I've done everything I could research. I may try another in the future, or just hold out for the next price drop.


Thanks again.