Overclocking help - beyond 2.8Ghz (E6400)

[Fulmar]

Recently, I purchased some faster ram for my computer in an attempt to overclock more than what I was currently at.  Before, I was using  DDR2-667mhz on my E6400 for a mild OC from 2.13ghz to 2.66ghz.  Never had an issue for a year.  When I first got my new RAM, I tried to go to 2.8ghz right off the bat figuring I had such easy success with the 2.66ghz.  No problems there.  Temps were fine, passed Prime95 etc.  So I took a risk and tried it at 3.2ghz the next step.  Not stable, failed Prime95.  Backed it down to 2.93ghz (733 FSB - 733 Mem), same result.  Did fine on Prime95 (only 1 hour tests), but I would get frequent crashes of Steam, Firefox, or any major applications.  3dMARK06 would start out fine, I'd leave the room to find that my computer had rebooted.  I sat and watched it the next time and saw about a 2 second BSOD before reboot.  Temps remained fine.

Long story short, I cannot seem to overclock beyond 2.8Ghz.  I've adjusted the Vcore and have done the standard increments, reboot technique.  See Bios Settings.  At current, my cores don't reach past 48C on full load at 2.8ghz (350/700).  At 3.2ghz I was getting varied results depending on Vcore setting.

Any help would be appreciated.

Hardware Specs: (age of Mobo, CPU, GPU, PSU is 26 months)
Asus P5N-E SLI (bios version 1201)
Intel C2D E6400 (stock 2.13ghz)
Arctic Cooler 7 HSF
Arctic Silver 5
G.Skill HK 4GB (2x2gb) DDR2 800mhz (4-4-4-12) 1.8-1.9V
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231219

EVGA Geforce 8800GTS 640mb
Sound Blaster X-FI Fatality
XCLIO GREATPOWER X14S4P4 600W PSU
http://www.newegg.com/Product/Product.aspx?Item=N82E16817189007

2 x Maxtor DiamondMax 10 6L250S0 250GB 7200 RPM SATA (RAID 0)
Seagate Barracuda 7200.11 ST3500320AS 500GB 7200 RPM 32MB Cache SATA
NZXT Lexa Case

120mm intake fan (2000RPM) - front
120mm intake fan (2000RPM) - side
120mm exhaust fan (1400RPM) - rear
80mm exhaust fan - top
PCI Slot fan
2 x 40mm glued side by side attached to the top of NB HS

Windows XP Pro SP3

BIOS settings - Currently  2.8ghz
FSB - 350mhz
DRAM - 700mhz
CPU multiplier - 8.0
Vcore voltage - 1.35 (increasing during higher OC's has not provided stability, have taken it as high as 1.47V)
Mem Voltage - 1.92
Northbridge - Auto (have not attempted to chance this)
Vcore Offset - Auto (have tried the other option of +100mv, no change in stability)
SLI Ready Memory - Disabled

CPU Internal Thermal Control - Disabled
Limit CPUID MaxVAL - Disabled
Enhanced C1(C1E) - Disabled
Execute Disable Bit - Enabled
Virtulization Tech - Enabled
Speedstep - Disabled

tCL (CAS) - 4
tRCD - 4
tRP - 4
tRAS - 12
Command Per Clock - Auto

CPU Spread Spectrum - Disabled
PCIE Spread Spectrum - Disabled
SATA Spread Spectrum - AUTO
LDT Spread Spectrum - Disabled

LDT Frequency - 5x
HPET Support - Enable

[BaldEagl]

Sounds like memory errors.  Unlink the RAM.  Set it to it's stock settings (800/4-4-4-12/1.8-1.9V) then go back and play with the CPU.

Once you have the CPU set then you can play with the memory if you need to.  Having the memory running faster clock speeds than the CPU's not going to hurt anything.

[Getback]

20% is pretty good OC and you're at 2.8 or a little over 30%.

[TilDeath]

Bump your NB voltage to 1.45 an see how it goes.  Your processor voltages are ok but you BSOD is ram related.  It will take a good bit of tweeking.  When OCing a rig, start with the processor and keep the ram at pretty much stock,  find a stable OC within temp limits for the processor.  Then start on your ram making sure you manually input the voltage and timings per manufacture ratings.  Also look at the advanced timings specifically the tRFC and try a manual setting of 72  adjust up and down no more then 2 steps at a time (ie 72 to 70 or 72 to 74)  OCing a Rig for max performance is a time consuming process, but can be very rewarding when you see those 3DMark scores climb a little at a time.

PM me if you need additional assistance.

TD

[MrRiplEy[H]]

Have you locked our PCI-E and PCI buses? Some boards overclock them too when you push the cpu. If your bios has an option to separate PCI bus speeds from FSB do it.

PCI devices respond badly to higher bus speeds usually and crash the box.

[TilDeath]

Have you locked our PCI-E and PCI buses? Some boards overclock them too when you push the cpu. If your bios has an option to separate PCI bus speeds from FSB do it.

PCI devices respond badly to higher bus speeds usually and crash the box.

Agreed.... set it to between 100 and 110

[Fulmar]

I guess I didn't post it in the BIOS settings, but it is set at 100

[Fulmar]

I solved it.  I'm stable at 3.2ghz now.  Upped the NB voltage a bit.