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Volts Question: E8400 to 4GHz.

3K views 40 replies 16 participants last post by  00t 
#1 ·
Okay, so I've put my new E8400 in today and I'm determined to get it to 4ghz with my zalman 9500 cpu cooler helping.

I've never played with volts while OC'ing before, and I know I'll need too. My only question is, what is a reasonable volt jump? My cpu atm is on 1.225v and I'm wondering in what steps I should up it too if I find my pc not booting while I up the fsb.

EDIT: Okay so after a lot of stuffing around, I can only manage to get my cpu to boot at 3.5 without freezing
I've tried upping the NB volts, running 1:1 with my ram, changing ram volts, and of course upping Vcore. None of this is successfully helping. Highest Vcore I ran at was 1.33, but the strange part is that I'm pretty sure CPUZ didn't read it that high.

I noticed in my BIOS that under a different tab (Power > Hardware Monitor > Vcore Voltage) my Vcore is set 1.21... and the only other option I can change it to is "ignored". Should I change that at all? CPUZ says my cpu is at 1.225 but my BIOS in my cpu volts bit is set at 1.23 atm. Pretty sure it doesn't change from 1.225 in CPUZ if i go higher, either.
 
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#3 ·
Okay cool, so there's no really harsh jumps for vcore?

Also, I just noticed my motherboard is saying my cpu is at 1600 FSB, but cpuz is saying it's at 1400...Could this be a voltage problem too? I've had it at 1600 FSB and running before, without changing volts.
 
#4 ·
45nm = stay less than 1.4vCore. No 24/7 overclocks higher than 1.362 vCore(recommended)

Suicide runs at 1.6vCore have been done by some crazy guy (me) and a Q9450 lol.....
 
#6 ·
That's all disabled, but for some reason it won't boot out of BIOS past 3.5 now. Max volts I tried was 1.3, but I haven't gone any further. I'm thinking it could be a memory thing... I'm still running my ram at 800hmz. Should I have it linked at 1:1 or unlinked and keep it at 800?
 
#7 ·
Quote:


Originally Posted by KHORR
View Post

That's all disabled, but for some reason it won't boot out of BIOS past 3.5 now. Max volts I tried was 1.3, but I haven't gone any further. I'm thinking it could be a memory thing... I'm still running my ram at 800hmz. Should I have it linked at 1:1 or unlinked and keep it at 800?

I would run it unlinked for now.

Perhaps try upping your NB voltage? ~1.4V is where I would set it at. But 1.35V or so should be your CPU voltage for 24/7 usage. Above 1.36V is asking for trouble, though it's OK as a suicide shot. I have booted as high as 1.425V in order to hit 4.2 GHz stable, but I run it under 1.3V for all day, every day use.
 
#8 ·
My PC isn't on 24/7 anyways, I turn it off every night before bed.

So I should put my vcore at 1.3-1.35 for now and try push it as far as I can? In what increments should I up my FSB?

Thanks for the help
 
#9 ·
I usually up my FSB 10-15 MHz at a time. Once you get past 400 FSB, I'd start doing 10 MHz increments, just to find the breaking point.

As for pushing voltage, the 45nm chips are more sensitive to high voltages, so I can't recommend you run it over 1.4V. Of course, I ran mine higher than that, but I can't guarantee you won't damage your chip above 1.4V. I would just play it safe for now, and hopefully you can hit 4 GHz. Best of luck.
 
#10 ·
So once you up it enough to reach the non-post point, you up the voltages a little? Thanks a lot btw, for all your help
I've bumped my NB volts up to 1.4 now. (1.39 for my board)
 
#11 ·
ARGH I can't get this thing stable past 3.5 now. I've had my NB volts at 1.39, my vcore at 1.33 and it's still not stable past 3.5. What am I doing wrong
I'm running it unlinked so my RAM is at 800mhz, and I haven't touched the volts for it. Could that be my problem? Or should I just try push the vcore more?
 
#14 ·
Just running your RAM at the lowest Ratio, 5-5-5-15 timings, at 2.1 or 2.2V should make it so your RAM isn't the thing holding you back.
 
#16 ·
I tried running it linked at 1:1 with my ram at 2.2, NB at 1.4, vcore at 1.3+ and it wouldn't even post. I tried unlinking again and running ram at 800 but still won't even boot at 3.53+, and if it did it would freeze before it fully started up.


I have to go to bed anyway, damn work tomorrow. Maybe I should give my cpu some more time to settle before i push it. I've only had it a few hours, lol.

My temps are all fine too, I have no idea what I'm doing wrong. Little bit disappointed
Thanks a lot for your help so far guys.

EDIT: I just noticed in my BIOS that under a different tab (Power > Hardware Monitor > Vcore Voltage) my Vcore is set 1.21... and the only other option I can change it to is "ignored". Should I change that at all? CPUZ says my cpu is at 1.225 but my BIOS in my cpu volts bit is set at 1.23. Pretty sure it doesn't change from 1.225 in CPUZ if i go higher, either.
 
#18 ·
Had my 8400 stable at 3.9g 1.39vcore (bios) , get into windows 1.36vcore (.03vdrop) , + .02-.04vdroop (1.344-1.322vcore) during prime 95 stressing. Just lowered it back to recommended 1.36 vcore in BIOS , 1.32 in windows , 1.318 prime 95. Still at 3.9g , prime didnt last 45 seconds lol. If that helps you any. MCH +.1v , DDR +.3v 5-5-5-15. Going to have to downclock or run at 1.39 which im scared to 24/7. When intel says reccomended 1.36 vcore , is that in BIOS or in Windows?
 
#19 ·
Quote:


Originally Posted by slyoteboy
View Post

Had my 8400 stable at 3.9g 1.39vcore (bios) , get into windows 1.36vcore (.03vdrop) , + .02-.04vdroop (1.344-1.322vcore) during prime 95 stressing. Just lowered it back to recommended 1.36 vcore in BIOS , 1.32 in windows , 1.318 prime 95. Still at 3.9g , prime didnt last 45 seconds lol. If that helps you any. MCH +.1v , DDR +.3v 5-5-5-15. Going to have to downclock or run at 1.39 which im scared to 24/7. When intel says reccomended 1.36 vcore , is that in BIOS or in Windows?

The voltage in windows is the one you should worry about the one in windows is the actual voltage going through your cpu while your BIOS Vcore is just what your board thinks it is putting out
 
#22 ·
Quote:


Originally Posted by slyoteboy
View Post

Tried 4.0 at 1.36v , not stable at all. Back to the drawing board. And whats better for memory performance , tighter timings , or higher frequency. I Dont think my memory will do 4-4-4-12 @ 1041. Thinking about dropping the multiplier getting more frequency.

It depends, really, but I think the consensus is that higher MHz is better, except for in very select situations.
 
#24 ·
I'm having a hard time overclocking my e8400 also. It seems no matter many setting I put it at, I can't get it stable. I know its not my ram, I've tested it at factory setting and primed it for a few hours. I just don't know what to do at this point.

Does anyone know the stock setting for my CPU vcore, the MB's NB, SB, and HT? Maybe if I get an answer there I have something to work with.
 
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