Hi and thanks for the help in advance. I've finally put together my rig and here are the specs:
Case- Antec 900
Motherboard- Gigabyte DS-4 (N650SLI-DS4)
GPU- EVGA 800GTX
PSU- 700W OCZ GameXStream,
CPU- Intel Core 2 Duo E6600
RAM- G. Skill 2GB DDR2 800 (PC2 6400)
HD- Seagate Barracuda 7200.10
DVD- Samsung 18X DVD+-R
Cooling- Scythe SCNJ-1100P (wasn't able to put in the optional fan, but may find a place for it) and Arctic Silver 5 Thermal Compound
OS- Windows Ultimate 32 Bit
At idle the Core Temps are around 35-38C, so it seemed to me that there was ample overhead to start overclocking.
Well, I modified voltages and FSB and got an overclock of 3.1 but here's where the trouble begins. I run dual instances of Prime95 for 2 hours and the overclock passes the inspection (CoreTemp gives temps at load to be 56-58 C, no erros). However, within 10 minutes of closing the program, my computer freezes up. Upon rebooting in about 10-30 minutes the same thing will happen, the computer will hang and freeze. Not wanting to take any chances I went back to the bios and went back to stock settings. There must be some voltage that I'm forgetting to change. Does anyone have a similiar rig and have good settings that they've used for voltages? I forgot to record the settings before putting the bios back to stock settings, so I'll be starting from scratch. My goal is to overclock this e6600 to somewhere in the 3.0-3.2 range. I've read the C2D overclocking guide and since there are some things in the bios that don't exactly match up to what I have in my bios. Thanks for the help!
before anything 2 hours prime stable is not enough, stress for at least 8 hours, i had orthos/prime fail on me on after 12 hours so never only run for 2 hours
1. never pump the core voltage first, bump fsb until its unstable
2. when max fsb for that voltage is reached, then bump up core voltage 1 notch at a time and test for that fsb
3. if stable, keep upping fsb and repeat step 2
now here is what you want: when it seems that you've hit the wall for fbs and vcore you can mess with fsb voltage, chipset voltage, and memory voltage. do the same thing and up them one notch at a time and test for stableness. mem (don't go over +0.3) and chipset first.
just note that don't go crazy overvolting because WILL it damages your pc
nice rig btw, how much is it?
ps oh ya also 3.1ghz is not that bad, and chipset voltage in ds3 is name MCH something
I think I've found stability overclocking to 3.15 GHz, but I want to run the BIOS by everyone just to see if there's something I've overlooked. Here is what I've modified, anything else that is in the BIOS that isn't listed here I kept at stock options:
Advanced BIOS Features
HDD SMART Capability [disabled]
Limit CPUID Max. to 3 [disabled]
No-Execute Memory Protect [disabled]
CPU Enhanced Halt (C1E) [disabled]
CPU Thermal Monitor 2 (TM2) [enabled]
CPU Eist Function [enabled]
Virtualization Technology [enabled]
Delay for HDD (secs) 
System Voltage Control [Manual]
DDR2 Voltage Control [+0.300V]
NT/HT-Link Voltage [+0.10V]
FSB Voltage [+0.10V]
South Bridge Voltage [+0.10V]
VCC12_DL Voltage [Normal]
CPU Voltage Control [1.37500V]
How does everything look? Do you think my voltages are reasonable? Stability wise, the overclock went through a 6.5 hour Orthos test and had no errors. Thanks to everyone for their patience, as this is my first time overclocking (my first build too actually). Thanks for the help in advance!
Penryn--> the rig cost me about 1700 out of pocket, but 1600 after rebates (I think the rebates are on the PSU and the GPU).
i'd disable the advance bios features like the cpu thermal monitor (its not the temp censors don't worry) eist func, virtualization as you don't need them
and also isee that you increases all the other voltages lol, did you test each one for stability? try to minimize voltage increases
and you are running 7:8 ratio fsb:mem. change your memory frequency to 700 for 1:1 ratio it results in better performance. I know you have to underclock your ram but it'll result in much better performace, trust me, do some benches and you'll know. You can lower the ddr2 voltage and tighten the timing (try for 4-4-4-12)