help with o/cing E8400 C0

twist3d0n3

twist3d0n3

twist3d0n3

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hi, i'm having a few problems getting my E8400 past 3.6GHz stable. I've ran orthos small FFT which gave an error after about 23 minutes, whilst the blend test ran fine. CPU temps never get above 55 degrees, but i've found in the bios that the north bridge has been hitting 73 degrees :eek: - i'm absolutely sure its this which is causing the instability. Anyone know what Vnb should be to run stable? its on auto atm as i'm not sure what to set it to.

system as in sig, with a zalman 9700 cooler.

cheers
 
I had mine at 1.3v at about 3.7GHz but now got it up at 1.38 at 4GHz. Temps were only hitting 42 under full load (according to asus PC Probe in windows)

What kid of airflow do you have through you case? I have put a fan blowing over the nb area but even before that the temps were not that high. What were yours hitting at stock?
 
i've got a lian-li PC-A70, which has 2 120 intakes at the front, 2 more on the other side of the hd rack, 2 120's venting. i could probably squeeze an 80mm fan ontop of my sound card and see if that keeps the nb cool. stock, if i remember correctly was reaching about 55 degrees, which is still pretty high imo

thanks for the info
 
tried it was 1.35Vnb, and it lasted 5 min 27 sec. i think pc probe is reporting incorrect temps/voltages - cpu temp in CORE TEMP was hitting 55 deg, whereas pc probe was showing 46... this is my first time o/c'ing an intel chip, so sorry for the nooby questions! also, does anyone recommend anything for PLL voltage? thanks!
 
No worries mate its my first time too so lot to learn myself :)

I dont think i upped the pll voltage at all just set it at 1.5v. What it reading at in the bios ?

PC Probe started playing up for me too. Its temps were a lot lower than coretemp/real temp which i would prefer to trust. Use Core Temp 99.3 and realtemp 2.75 and they should both read the same. It will be the 55c reading unfortunately.

Is the nb still reading 73c in bios? Thats definately too high if it just idle. What was pc probe showing for it in windows?

Best to set all the voltages manually rather than leave on auto.
 
i just tried pll @ 1.5, and orthos didn't like it, so for the time being i'll leave it on auto.
i've got core temp 99.3 running so that should be the correct temps.
the NB has dropped to around 55 deg in bios so thats far more comfortable, i'll try sticking a fan on it later on today.
i'll have to do a bit of research into pll voltage/fsb terminal voltage cos they're completely new to me (had an athlon x2 6000+ before, and before that i had a athlon x64 3200+, which had a lot simpler setting imo). i read somewhere that turning off spread spectrum can help with stability, so i might have a look into what a lot of the settings are and if turning them on/off will actually help. i'm starting to think i might have a pants overclocker :(
 
Yes i put the spread spectrum thing off too.
You havent said what vcore you are running at?
What speed and voltage is your ram at?
 
What the VID of your cpu according to core temp?

I would say that you need to up the vcore a bit. Is the 1.15v at load or at idle. Either way it will need a bit more juice.

Mines at 1.33v in cpu-z but that drops to 1.3v underload.

edit: meant real temp 2.79.8 in previous post
 
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i'm getting 1.225 for vcore under load, 1.15 idle. these are both taken from core temp. got real temp installed now, and it shows same voltage/temps as core temp so i think its safe to say they're giving me fairly accurate readings now. i'll up the vcore a bit and see if i can get this completely stable. cheers for your help mate
 
something wierd is happening even though i've set the vcore to 1.3 it's still saying it's at 1.225 load/1.15 idle in core temp and real temp. Pc probe strangely says vcore is 1.3v. i'm baffled!
 
what voltage is your NB at?

if its on auto then that could be the reason for the heat

also my northbridge dropped by 10'C when i installed my vga cooler as the fan off that cools the nb too
 
i've got the north bridge at 1.37v, i did think maybe it was corresponding to a different voltage i may've set, but its definitely not. For some reason, after changing load line calibration to diabled, i've got it stable at 3.8GHz, on vcore 1.310 volts, even tho real temp and core temp say vid is 1.225v under load. Currently i'm running orthos small fft, and i've been going for 45 minutes, so i'm taking it as a good sign, cos before i changed load line setting, i was lasting about 1 minute lol

edit: NB temps are hitting about 55/60 degrees under load, so i'll be whacking a fan over the NB heat sink asap i reckon
 
VID isn't a changable reading...its what each individual cpu needs to run at stock speed. Dont worry...only just learn myself that its different for each cpu depending on how it tests at factory. Mines a 1.225v one too.

CPU-Z is the best thing to find your actual vcore.

Got mine stable now at 4GHz with 1.30v vcore under load. Got close to being stable at 4.3GHz but needed to go up to 1.38v to get there so decided to leave it...for now at least :) My pevious Opty 165 (R.I.P.) died an early death due to having highish (1.52v) voltage through it for a couple of years so going to play it safe i think.

Definately get some airflow over the nb. Just reinstalled pc probe and realised mine was at 48c at idle with 1.38v on it. Had the fan for it turned down low....too low its seems. Turned it back up and now back down to 37c. South bridge is at around 30c.....thats at idle mind.
 
ahhhh, that explains it :D thanks for the info

i've just ran orthos for 3 hours on blend whilst i went out, and it was still ticking when i got back so i think i've got it nice and stable - might have to push for 4GHz now ;)

these chips are (according to the intel data sheet) safe up to around 1.36v i believe, so i'm going to stay under that unless i take the leap to water.

what process was that opty on? (90nm/60nm?)

just out of interest, how do you get pc probe to control fan speed? i tried moving the threshold slider, and it just came up saying it was over the temp, whilst not actually doing anything to the fan speed... on my old amd 6000+, i moved that slider and it got the fan to kick in a bit sooner
 
The opty was a 90nm chip.

Not sure how to get pc probe to control fan speeds. speedfan wont do it for me either with cpu fan but will with the memory cooler i have just got. Probably just me got something set wrong.

Yeah go for 4 :) Its a nice round number :)
 
i gave it a whirl, and it didn't like it at all! booted into windows, and after about 5 seconds of the desktop rebooted itself :D think i'll have to tinker with nb/fsbt voltages a little bit.

got it up to 3.85GHz, going to run orthos when i go out a bit later and see if its still alive when i come back lol

many thanks for your help, really appreciated!
 
hello all , i just got a e8500 with gygabyte x48-ds4 and 6 gig of ddr2-800 ram x2 x2 x2 , im just wondering if this will be posible for me to overclocked it to 4 ghz??? and also one thing i want to know one of my core run higher than the other like 10 or 8 degrees celcius difference is that safe?? and whats the maximum safe temperature for E8400 ?? mine goes up to 55 degrees on load !!, help will be appreciated , thank you in advance
 
Should be able top get it to 4ghz.

My old one (C0) managed 4ghz on 1.3v and the one i have now (E0) is @ 4.5ghz on 1.31v.

New one runs 30c idling and 54c full load @ 4.5ghz.

Your temp difference between cores could be to do with the heatsink contact. Is it the stock cooler?

gt
 
hi

i have a freezer pro 7 cooler and i did remove it because i had a new power suply to put in to work with my new graphic cards , what are the setting in bios to get 4 ghz stable and safe temp? my cooler is secure and seated i check the 4 pin and it looks like its in im thinking maybe not enough thermal paste , if i buy some thermal paste should i just apply over the layer cause i just recenty got this pc or i have to remove the thermal paste on their already before applying the new one?
 
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