Trying To Get To 4.0ghz W/ E8400 + 780i

[cybereality]

I've read tons of guides (here and other places) on overclocking, I think I have the basics, but this is my first time so please excuse any newbie mistakes. I'm running with the hardware in my sig, mainly an Intel E8400 and EVGA nForce 780i mainboard with 2x2GB of Crucial Ballistix DDR2-800 RAM using water-cooling.

 

I've got my E8400 running at 3.6GHz currently which seems fairly stable. I can boot into windows Vista (32-bit) and I've ran Prime95 for about 30 minutes w/o errors. Watched a movie, ran 3dmark06 twice, and played a few games without issue. Temps are fine, around 33C idle, and 45C load. All I did was adjust the FSB to 400MHz, timings on the memory (4-4-4-12) @ 400MHz linked/synced w/ FSB, CPU multi set to 9. I left all the voltages at auto, Vcore is at 1.31 in BIOS. All speedstep, C1E, etc. is disabled. So far so good.

 

Now I am trying to get to 4.0GHz but I'm having some issues, maybe someone can give me suggestions. To get 4.0GHz I set the FSB to 500MHz, CPU multi to 8, RAM set to 5-5-5-15 @ 500MHz (linked/synched), speedstep/C1E disabled, and left everything else at auto. I can boot into windows, no problem, and little applications seem to work like CPU-Z and the temp monitors. However if I try to run Prime95 it fails within seconds. Temps look normal, 35C idle, 48C load. Whats the most likely reason for this?

 

 

I assumed the CPU voltage might have been too low, so I bumped it up a notch (from 1.31 to 1.32) but then my PC freezes mid POST. You hear the beep, but it never gets past that point (it just stops with the CPU check on the screen and nothing else). I had to reset the BIOS with the jumper (but not before I almost had a heartattack!!!).

 

Do I need more voltage or less maybe? I don't want to fry my chip just trying different values if I really don't know what I'm looking for (I'm not interested in running over 1.4v). I'm thinking it might have also been the RAM, its set at 1.85v and its suggested I set it at 2.1v. However, I'm not really sure. Again, I was able to boot up with these settings, its just not stable. What do I do?

 

Also, should I just be happy with the 3.6GHz overclock? Is 4.0GHz too extreme to run 24/7?

Edited May 17, 2008 by cybereality

[jelly]

I think befor you start rasing you cpu volts you need to find the max speed that your ram can run. By you setting your fsb to 500mhz and keeping you memory synced with the fsb your running you memory over its rated speed. Your fsb is 500mhz but with ddr ram you double that (500mhz x 2 = 1000mhz ddr) and your ram is ddr800 thats (400 x 2 = 800mhz ddr). So to find what your max ram speed is take you multi from 9x to 8x and keep you fsb/mem syced and just up you your fsb by 5-10mhz and run mem test to check if the overclock it ok, then boot into windows and run superPi to check for stability. If it passes then go back to your bios and repeat till you get instable. I would also put your memory at its rated volts 2.1v. I know this is for the A64 but the theory is the same. link

[CanadaGUY]

If you had a heartattack cause it wouldn't post, I'd maybe stick with the 3.6ghz Hehe, cause that may happen alot while you try to grab that 4.0ghz.

 

Take jelly's advice and do some gradual OC'ing, while stress testing all the way up. OC'ing to the next level takes some time, days, maybe weeks to find the right settings. So take ya time, drink some nice wine (that wasn't on purpose), and get ready for some sweet OC's

[Syngensmyth]

Also, should I just be happy with the 3.6GHz overclock? Is 4.0GHz too extreme to run 24/7?

I don't believe GHz can be classified as too extreme one way or the other. Temps can be classified that way, however. So if you can get 4 GHz with suitable temps = happy.

 

Jelly has said it exactly right. Once you find the RAM top, there is a way to take the CPU bus further than the RAM by dividing the RAM/CPU bus ratio (Is that the "strap" with Intel language, I'm not sure). This CPU/RAM speed relationship is essential to understand for overclocking beyond what you have done already, which is simply cranking up the FSB. But hey, that works too, as far as it goes.

 

I know it is a pain to take the speed up so slowly but at times this gradual ramp up can work when jumping the same amount in one step does not and it is a safer way of doing things. As a new OC'er it gives you a better feel for what is going on ... an added advantage.

 

Good luck to you. :thumbs-up: