Overclock my Core 2 Duo E8200

Yeah, it's ok, but the stability of your system has to be tested now. While testing the stability, watch the temps using Real Temp (it will go by Celsius which is the standard). For the sake of avoiding instability caused by heat, try to keep the temps out of the 70s and 80s.

Also, watch CPU-Z for the core voltage. Keep that under 1.45V as shown by CPU-Z.

You can also seek more help at www.Overclock.net.

AddRAM said:

Where did you get your info from ?

Over 3 years of daily exposure on Overclock.net (12+ hours per day, sadly, sometimes 18+ hours - but I love that place). There was an official Intel PDF posted somewhere that shows that 1.45V is their absolute maximum recommendation for a core voltage. The temperature-related information is a combination of my experience with an E8400 and my experience on Overclock.net including all of the help I received overclocking mine to 4 GHz.

I also learned along the way that 95 to 100°C is the temperature where the CPU will automatically throttle itself down (it's the Tj. Max, or "Thermaljunction Maximum"), so that's essentially the maximum safe temperature. However, instability is far more likely to occur before it ever gets that high, especially if the CPU is under load. That usually happens in the 70s and 80s.

I know that Intel has a VID Voltage Range stated on their site of 0.85V to 1.3625V, but the VID Voltage Range is just the voltage that the CPU can request from the motherboard when the voltage is set to Auto and it's not related to the minimum and maximum safe voltages. I was using 1.368V for my E8400 when I had it in an EVGA 680i SLI for about a year, but that's not how I learned that going above 1.3625V is safe.

I also know that they show a T Case temperature of 72.4°C, but that's measured at the "geometric center on the topside of the CPU's integrated heat spreader", according to Intel. This is the same place that makes contact with the heatsink. Usually, the Tj. Max is about 20-25°C higher than the T Case.

As we say on OCN a lot, "OCN FTW". The knowledge one can gain over there about this stuff is just as amazing as the knowledge one can gain over here about Windows 7! If it weren't for them, then I'd still have a cheap pre-built from the Windows 98/2000 era and that's the era where my knowledge would be strongest in too.

Oh, for that small of an overclock (3.0 GHz), the voltage can be set so that when you're in Windows looking at CPU-Z, it shows about 1.25 to maybe 1.27-1.28V. That should be enough for an overclock this small (if anything, perhaps more than necessary). Due to a combination of vDrop and vDroop, you may need to enter a BIOS setting of like 1.35V to start with and work your way down from there in order to achieve this voltage (to see it in CPU-Z).

The VTT FSB Voltage should be ok at 1.20V, but you may also need to increase it one increment up (that is, if the next increment is 1.25V). It's a little bit similar to the core voltage because it's powering the FSB in the CPU, so stay under 1.45V for this too.

Everything else seen in the photo should be ok left where it is.

When I had my E8400 in my EVGA 680i SLi, I got it up to 4.0 GHz and I had to increase the FSB voltage to 1.4 too. :) So, I had a core voltage at 1.368V with a FSB voltage at 1.4V, but that's nForce boards for ya. They love the voltage. I even remember having to increase my NB voltage a bit, but the SB voltage didn't need to change because the SB doesn't control much that's related to overclocking the CPU.

AddRAM said:

So don`t touch the FSB Clock that`s highlighted ? I thought you would adjust that too.

I thought you did and this was an older photo from before you did.

For 3 GHz, 1333 would be changed to 1500. The FSB can be thought of as having a multiplier of x4.0 at all times (Quad Data Rate, or "QDR"). The E8200's highest multiplier is x8.0. So, 3000 (3 GHz) divided by 8 is 375W. 375 MHz is the actual Bus Speed. 375 x 4 is 1500, so that's the FSB Clock Speed you'd need to enter for 3 GHz.

Just to make it clearer if need be (if even just for someone else reading this), the stock speed of the E8200 is 2.66 GHz which is 2660 MHz. So 2660 MHz divided by 8 is 333 MHz. 333 MHz x 4 is 1333 MHz. Using a calculator, the numbers are slightly different, so I'm using the advertised numbers. :)

Edit: When you increase the FSB Clock, the memory will go up along with it. I'm not sure about the 750i, but look for an option that might be called "FSB - Memory Clock Mode". One of the options for the setting I'm looking for is Unlinked, and this can help keep the memory closer to 800 MHz, and sometimes even exactly 800.

I made an edit to add that if you increase the FSB Clock, then the memory clock will go up with it. If this board has any option to choose a setting that will be called "Unlinked", then use that. My EVGA 680i SLi called it "FSB - Memory Clock Mode", and I think it had the same name in 780i boards too.