E6600 lost stability at 3,6ghz, after 2 days of perfect stability

well the offical spec from intel states that 1.5 is the max vcore for the cpu...I would personally never go near that for air cooling or a 24/7 oc....the highest I would go would be 1.4v.....It seems kinda fast for damage to the cpu but it is def possible at that high of a voltage

Any advice as to how to proceed from here on? I'm currently back to my previous overclock @ 3,4ghz, 1.485 vcore

Oh, and thanks ofcourse  

why do you have the voltage so high? is it unstable at normal vcore levels? If so you got a really bad OC'ing chip lol one of the worst ones I have seen yet. if you cant get it stable you cant get it stable unfortunately.......if you are really intent on overclocking really high you could always try to pick another one of these cpu's up from ebay for like $30 bucks or so....but I wouldnt drop any more money into it...maybe its time for an upgrade (cpu/ram/mobo) if the funds allow, even a cheaper i3 will blow this cpu out of the water when it comes to anything

That's not entirely true, i've been able to play everything up to Battlefield 3 (ofcourse not at max settings, but who uses that anyway). Don't under-estimate my setup. Thing is, I don't have much money and I have always had more of a mcgyver approach when it comes to my computer.

Also, the stock speeds of my C2D are 2,4ghz with 1.325v vcore. So yeah, I do realise what i'm doing to the chip.

I've been running it at 3,4ghz the past couple of months, tried 3,6ghz the last couple of days, then after I pushed it over 3,6 with a little extra vcore I haven't been able to get it back at 3,6ghz again. So i'm sitting at 3,4ghz now.

Also, my idle temperatures are usually below 30 (cpu) and load 43 (MAX!)

thats good...i am not underestimating your rig at all....it just seems that you are not happy with the current performance of it if you are trying to push the chip so hard (thats why I recommended an upgrade).....unfortunatly there is not much you can do besides take alot of time and mess with the settings on the OC....do all different combos of vcore and fsb settings until you get it stable at the speed you want. (you may just need to push alot of vcore) and if thats the case dont expect the chip to last long...over time there will be deterioration and it will become unstable once again....what motherboard do you have this chip in? does it have a good clean power delivery system for the cpu?

My specs:

Mobo: Asrock P5B-DE http://www.asrock.com/mb/Intel/P5B-DE/

CPU: Intel E6600 Conroe, stock vcore = 1.325, stock speed = 2,4ghz

RAM: 6gb DDR2 801 (regular RAM)

GPU: xfx 9800gtx+ 512mb DDR5 (factory oc'd)

CPU cooler: Coolermaster Z600 http://www.coolermaster.com/product.php?product_id=4509

Side note: I used the cpu for years in a Asus P5PL2-E at 3,2ghz, but that mobo had an overclock barrier. This board overclocks WAY better. 3,4ghz has proven stable for a long time on that board, and it passed stress testing at 3,6ghz too. I'm just hoping that maybe when I try the 3,6ghz settings tomorrow it'll miraculously work again   (I really can't afford to spend any money on my rig)

EDIT: Also, 500w 85+ power supply

I hear ya man times are tough..I dont have any money to throw down on a pc upgrade right now either....havent upgraded my rig since 2009! lol its been light years for me. (I used to upgrade every few months) then college hit haha....goodluck on messing with the oc tomorrow sorry I couldnt offer a magic fix lol..let me know how it works out

Thanks a lot for the help man   Really appreciate it.

I'll definitely let you know how it worked out.

Hey man, about a week later now i'm still having trouble with the cpu. I managed to find a way to run it at 3,4ghz again, but it's way hotter because I have to up the VTT now.

Before I could just vcore my way (up to) 3,6ghz

My regular overclock was 3,4ghz, for which I know need to bump the vtt to 1.37 to get it stable.

3,6ghz, i can't get stable no matter what I try.

Aida 64 tells me the CPU is fine, but it's the FPU that's getting unstable.
So basically, my FPU (vtt voltage) has become unstable, any thoughts about that?

FPU what is that? and the VTT is like the FSB voltage right? Its been while since I have OC'ed socket 775 chips....if I remember correct the highest safe VTT setting is 1.4v what do you have it at now?

Uhhm, if I remember correctly the FPU is the memory controller in the cpu (like, it's the RAM-bus for the cpu). The VTT voltage is the FPU voltage I believe.

So in a CPU the cores and that memory controller have seperate voltages.

Auto used to do the job, for VTT, and vcore would be somewhere 'round 1.5v

I'm from the Netherlands btw so it's bedtime.

Oh uhhm, vcore 1.5250 and VTT 1.37 works for 3,4ghz (but it runs hotter than before because the VTT didn't have to be upped back then)

hmmm all signs are pointing towards the chip nearing its end of life....when you oc a chip for long periods of time it becomes unstable at settings that used to be stable. you having to up the vcore and the vtt voltage like this kinda makes it seem like this is what is happening to your cpu....how long have you owned this cpu and how long have you had it oc'ed with a high vcore?

I have used it at stock voltages for about 2 years, then overclocked it to 3,2ghz for about 3 years (All in my Asus P5PL2-E.

Then I ran it at 3,4ghz this year in my new Asrock P5B-DE. I ran it for 3,6ghz for about a week.
Then I tried to bump it even higher. And after that last increment, it has been unstable.

So it went wrong after 3,7ghz attempt.  

I know that it's a old cpu, but I always felt it was immortal.

Before I used about 1.425 vcore for 3,2ghz. 1.5250 (vdroop to about 1.5) for 3,4ghz, and about the same for 3,6ghz.

Also, I did bump the voltage to about 1.55v for the 3,7ghz attempt, 3,6ghz was hovering in between 1.55 and 1.5.

intel specs say anything over over 1.5v has the possibility of damaging your cpu...seeing that you ran it that way for over a year it doesn't surprise me that it is unstable at settings that it used to be stable at now. it makes perfect sense. unfortunately that means there really isnt anything you can do but back off the oc....or if you are really not happy with this you can try getting a new cpu off of ebay. you can get them from anywhere from $25 to $50 which is not bad at all

Alright, thanks for your help. I hope I can afford to replace it soonish, I managed to get a job so  
Hopefully it'll survive for a while at the slightly higher voltage so I can still play Battlefield 3.

Perhaps after that I can use it in a low-end system at stock speeds and voltages, I bet it could run like that for years to come.

yea I bet it would be able to run at lower speeds and voltages no problem for a good amount of time. Good luck with the job I hope it works out for you.