NB,SB and chipset voltages, what's safe?

[praesto]

Hey guys, I want to overclock my e4300 on my asus p5b-e plus mobo to 3ghz. I'm very hesitant, however, as I belive setting the NB/SB and chipset voltages to auto will result in my mobo getting toasted. I have rather good airflow in the case fyi. So, what do you recommend me to set NB/SB and the ICH chipset voltages to, if I want to reach 3ghz on my e4300?

Regards Hoger

[j4mes]

For one, never use auto setting you'll never be able to reach an overclock..

Secondly your NB voltage is not that sensitive to heat comparable to your CPU
So raise your CPU Volts as you cant be stable in windows and after you've gone two voltage steps in your BIOS i would give .05v to your NB, im not sure how the P5b BIOS is if its in .1v increments or .05 or what, but i would just go up one each time..

if you plan on going to 3.0, i would suggest not neading more than .2V to your NB and nothing over 1.475 to your vcore

[praesto]

Thanks for your response. I do not know what the standard values of the NB/SB/ICH chipset voltage are, so while I do appreciate your suggestions, I am not really able to use them .

[j4mes]

1.2750 vcore 1.5 NB/SB, youll have to reach around a 429~ MHZ FSB so if you have PC5300 RAM youll need to give more volts to your RAM to run at that speed, if you have PC6400 you shouldnt need to raise your RAM volts much higher than its rater Voltage

[praesto]

Alright thanks for your time J4mes, I'll try it

[j4mes]

no prob glad to help

[775911]

Whats a safe vcore for air cooling ? I have 1.52 at present

[fgw]

from looking into intel datasheets:

vcore 0.850 / ---- / 1.500 / 1.550
Processor Core Supply Voltage, applies to E4000, E6000 and Quad Core Processors

ddr2 see specs of your memory modules for voltage ranges
Memory Supply Voltage

mch 1.25v 1.188 / 1.25 / 1.313 / 1.375
MCH Core Supply Voltage (Northbridge)

ichio 1.5v 1.425 / 1.50 / 1.575 / 2.100
1.5V Supply for Logic and I/O (Southbridge - Internal Logic and I/O Buffer Voltage)

cpuvtt 1.140 / 1.20 / 1.260 / 1.320
System Bus Input Supply Voltage, often referenced as FSB termination voltage (VFSB) simply the voltage the fsb is running on. logic levels on the fsb are relative to this voltage. higher vtt results in higher logiclevels and thus in increased noise ratios. increasing vtt might help overclocking.

ich 1.05v 0.998 / 1.05 / 1.102 / 2.100
1.05V Supply for Core Well Logic (Southbridge - Internal Logic Voltage)

all voltage values: min / typ / max / absolute maximum

don't know if your p5b supports changing all this voltages. i have written this for the abit AB9QuadGT. as both boards use the same chipset, voltages are the same.

also have a look at post #53 here:
http://www.xtremesystems.org/forums/...=132728&page=3

[smsmasters]

good info thanks

[ziddey]

fgw, excellent info. ichio and ich have striking abs maxes!!

mch scares me a little in its definition of abs max.
same for vtt. didn't know it was that low

[Gam3Ra]

438FSB at minimum voltages stable here (P5B-D)
NB 1.25V, SB 1.5V, ICH 1.0xxV, FSB 1.2V

[ziddey]

man e64 @ 3504 1.22v?? that's beyond spectacular. i'd have a field day

[smsmasters]

438FSB at minimum voltages stable here (P5B-D)
NB 1.25V, SB 1.5V, ICH 1.0xxV, FSB 1.2V

What VID does it say for your cpu in core temp? Is it orthos stable?