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OCing q8400 with GA-EP43-UD3L FSB limited?

Discussion in 'Overclocking & Cooling' started by colzboppo, 14 Apr 2010.

  1. colzboppo


    Joined: 24 Feb 2010

    Posts: 520


    <-- Ocing N00b doh :(

    I'm trying to overclock my Q8400 past 3.3Ghz, and im hitting a brick wall. The PC just won't POST beyond a certain FSB rating.

    I've got a Gigabyte GA-EP43-UD3L Mobo, apparently on the box it says the FSB can go up to 1600Mhz.. I can't get the multiplier past x8, the multiplier fine tuning with a +0.5 doesnt register beyond a displayed figure on the post screen, it shows an actual x8.0 in CPU-Z once ive logged in.
    I've managed to get it to go up to 417mhz (1668 rated) which I thought is pretty good..


    Now question is, do you think there is anything I can do to push the FSB up a little further, the BIOS is a little confusing to me, but I have NB (MCH) and ICH I/O voltages to play with, and RAM voltages too. Is this going to help?

    Should I be trying to avoid overclocking this CPU any further? Looking at the voltage its set to auto in the BIOS, its pumping a beefy 1.34v into [email protected]/2.5. Is this an acceptable amount of juice to be playing around with on 45nm?

    Lastly, getting a titan fenrir to replace the stock cooler today so the temps will likely dive from a toasty 45c @ 25% load so dont worry about that.

    Gar.. Anyways thanks for any help.
  2. varkanoid


    Joined: 31 Dec 2007

    Posts: 11,646

    Location: The TARDIS, Wakefield, UK

    First off make sure your ram is running at its stock mhz. Dont overclock the RAM. That why you are not dealing with unstable RAM and CPU. 1.3v for the CPU should be adequate and you may get 4ghz with it. Main issue will be stock cooler. Not sure about the R0 revision. I thought C0's were better at reaching 4ghz.
  3. bifday2k


    Joined: 3 Jul 2009

    Posts: 2,601

    As ur allready going over the specified max FSB on the mobo, ur going to have to start raising the mch (Nb) voltages, some mobo's you don't need to but some you do, so try raising that a notch or 2.

    About the memeory, unless ur using 1066mhz memory, you will have to use a 1:1 fsb/memory ratio, and the memory will be overclocked, but you have qaulity memory, so that should be fine upto 900mhz if not more, just put the timings on auto whilst ur testing.

    After reading this on the Gigabyte site
    Front Side Bus 1600(O.C.)/1333/1066/800 MHz FSB

    Your basicly lucky to get it over 400fsb, as it dos'nt officially support it, only supports it via overclocking, so u can try what i suggested to see if you can get a tiny bit more out of it, but you will be lucky too. Sorry for the bad news.
  4. Temi_D

    Wise Guy

    Joined: 31 Jul 2009

    Posts: 2,177


    I am 100% sure that the problem is the mobo. I had a very similar problem with a P43-ES3G and my Q9650. Mine wouldnt boot past 410 in the bios and up to 417MHZ in easytune6. You can read it here:http://forums.overclockers.co.uk/showthread.php?t=18110115

    I then got a new mobo (P5Q Pro Turbo) and managed to push my chip to 4GHz on stock voltage: http://forums.overclockers.co.uk/showthread.php?t=18132323

    Also i think you should lower your voltage to stock as putting it higher isnt going to make a difference with that mobo
    Last edited: 14 Apr 2010
  5. colzboppo


    Joined: 24 Feb 2010

    Posts: 520

    thx for the responses. I'll see what kind of voltages I can get away with @ 3.33ghz, which seems to be the FSB limit.

    Although limited by the Mobo's FSB, its not too shabby, yes perhaps I could achieve 4ghz with a beefy voltage and a new Mobo, but i think having a stable OC @ a nice voltage with less risk is a nice compromise.

    Cheers for the help.