I am a total noob on building and OCing. Here is my spec and I ran Prime95 for 1 hour with no problem so far but the problem is the temperature is really high with core temp (highest is getting to mid 70s) tried lowering the CPU voltage but fail really fast. Any suggestion? Thanks for all your help in advance!
Lian-Li PC-A05B ATX Black Aluminium Mid Tower Chassis
Antec Neo Power Blue 650 Watts Modular 80+ Certified Energy Efficient SLI/Crossfire Ready Power Supply
Intel Core 2 Duo E8400
Asus Silent Square Pro Adjustable CPU Cooler with front fan speed display and control Knob
Asus P5Q Premium ATX Cross Fire Ready Motherboard with onboard EPU
ATI Diamond HD 4850 512MB PCIE 16X Video Card
OCZ Flex XLC 2GB DDR2 1150MHZ
CPU Ratio Setting: 9
FSB Frequency: 423
PCIE Frequency: 100
FSB Strap to NorthBridge: Auto
DRAM Frequency: DDR2-1127MHz
CPU Voltage: 1.34375
FSB Termination Voltage: Auto
DRAM Voltage: 2.10
NB Voltage: Auto
SB Voltage: Auto
Get speed fan and calibrate it so you know your Tcase temp. Unfortunately the only published max temp is the Tcase (core temperature readings are for tjunction). The e8400 Tcase max temps are 74c (e0 stepping) 71c (c0 stepping).
As for your settings. It looks like you have an awfully high vcore for that clock speed. With my e0 stepping e8400 I was able to hit 3.8ghz on stock vcore and was at 1.2something. I didn't have to start bumping vcore till I went for 4.0ghz (444x9) and even at that OC it was a very minor voltage bump. But your high temps are being caused by that vcore which is fast approaching Intel's specification of 1.3625v.
Something else to consider is that your video card puts out a TON of heat, and if you don't have good case cooling (at least 2 or 3 120mm intake/exhaust fans) your interior is probably roasting and causing the cpu to run hotter than it needs to.
So for starters, what stepping do you have? Try dropping your vcore to 1.265 and see if you are stable in prime small fft for at least 4 hours. If not, bump it 1 increment at a time until you get that kind of stability.
Yeah I just checked out your case on newegg, and it looks like the cooling system on that thing sucks big time. Sorry to be blunt, but that's not helping you. The easiest and cheapest solution would be installing 1 or 2 pci slot blowers. Short of modding the case to put another fan or two on it, I don't see much way of improving your ventillation. If you decide to mod the case so you can install some more fans, I'd suggest using the side panel (if it comes off). You could drill a bunch of holes in the side and install 1 or 2 120mm intake fans. Main danger of modding the case is you want to be sure that no metal shavings get anywhere near your components. Hence why I suggest the side panel if it comes completely off.
You have to remember that only 50% of the e8400s hit 4GHz at 1.4v or less. You are at 3.8GHz which is still plenty fast. Can you try adjusting your fan to max? If you want 4GHz at 1.2v, you are gonna need an e8600. Those are Intel's highest bin and im seeing people hit 4.5GHz at 1.3v to 1.4v Hope this helps.
Also, I dont know if it is my fan too... everything stock setting i get like 60sC when running p95. And it should be in Max fan speed as I can adjust it from the outside of my PC and it is 100% on the nob with 2220rpm speed.
My e8400 (e0) hit 444x9 at 1.25v vcore and that's all I changed
If you are hitting high 40s idle and low 60s loaded at stock settings, you probably should try reseating your heatsink. But before you do that, try running the prime 95 at stock settings with the side panel off and a fan blowing on your open comp--that is if you haven't already don this. That will tell you if your case cooling is causing you problems or if you need to reseat the heatsink.
just whack it up to 1.6v like me its fine, im stable at 4.6ghz. seriously dont put above 1.4v unless you have cash for new cpu. if its still not stable at a decent voltage try altering the pll and fsb term(vtt) voltages. google whats the safe limits i cant be botherd to do it for you.
i wish i could earn a living overclocking but like always you only get payed if you break the equipment not on how stable it is . if you live near the leeds area i could pop in and have a look for you i wouldnt chage anything except petrol.