AMD Athlon II X4 640 Overclocking

Currently in my BIOS i overclocked my CPU to 3.3GHz which was 10% according to the mobo. Could I go any further with it to maybe 3.7GHz or even higher?
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More about amd athlon 640 overclocking
  1. Of course you can go higher !
    But first check if your temps are ok.
    Do not attempt overclocking your chip if it's not cooled properly.

    The easiest way to do this is to reduce your North Bridge multiplier to 8x , reduce your memory clock by one step
    If your ram works at 1333 mhz, which is 667 times two, then reduce it to 533 (1066 effective) and the last thing you need to do is to increase your CPU's reference clock to 247 mhz which will enable a clock speed of 3705 mhz (Ref clock * CPU Multiplier = frequency).

    Note that your motherboard may not be able to handle such an overclock and your CPU might also be below avarage, so this is not sure to work.
    If it doesn't work and your PC is unstable, you will have to revert it back to normal.
  2. Kamen_BG said:
    Of course you can go higher !
    But first check if your temps are ok.
    Do not attempt overclocking your chip if it's not cooled properly.

    The easiest way to do this is to reduce your North Bridge multiplier to 8x , reduce your memory clock by one step
    If your ram works at 1333 mhz, which is 667 times two, then reduce it to 533 (1066 effective) and the last thing you need to do is to increase your CPU's reference clock to 247 mhz which will enable a clock speed of 3705 mhz (Ref clock * CPU Multiplier = frequency).

    Note that your motherboard may not be able to handle such an overclock and your CPU might also be below avarage, so this is not sure to work.
    If it doesn't work and your PC is unstable, you will have to revert it back to normal.


    Yeah my temperatures are fine, 9 derees at idle and about 20 degrees when doing medium to high demanding tasks :D Also im using the stock fan LOL My motherboard is the Asus M5A78L-M LX V2
  3. Can I ask what your ambient temps are? Damn, 9C at idle?
  4. ihog said:
    Can I ask what your ambient temps are? Damn, 9C at idle?


    not sure what you mean? I used hardware monitor to check my temps and it was 9 degrees idle, 20 degrees whist using chrome and steam at the same time and its about 35 degrees whist gaming.
  5. You would actually want to keep your IMC/NB at 10x --- reduce your HT Link to 8x.

    For each 10% you increase the IMC/NB speed, memory bandwidth is increased 3-4% and latency is reduced 3-5%. Running the IMC/NB at 10x250MHz (from stock 2000MHz) should provide a nice boost to your gaming, too.

    1.2v NB volts should handle it easily --- you could go even a little higher if necessary.
  6. ihog said:
    Can I ask what your ambient temps are? Damn, 9C at idle?


    not sure what you mean by ambient temps?
  7. Wisecracker said:

    You would actually want to keep your IMC/NB at 10x --- reduce your HT Link to 8x.

    For each 10% you increase the IMC/NB speed, memory bandwidth is increased 3-4% and latency is reduced 3-5%. Running the IMC/NB at 10x250MHz (from stock 2000MHz) should provide a nice boost to your gaming, too.

    1.2v NB volts should handle it easily --- you could go even a little higher if necessary.



    stock is 3000MHz :P
  8. That's room temp.

    Stock IMC/NB speed is 2000MHz (10x200MHz).

    Stock CPU speed is 3GHz (15x200MHz)
  9. Wisecracker said:

    That's room temp.

    Stock IMC/NB speed is 2000MHz (10x200MHz).

    Stock CPU speed is 3GHz (15x200MHz)

    ahh room temperature is about 18 degrees C, but cooling is helped by a 140mm fan and 120mm fan that came with my case + the stock fan. Without including the psu fan and 2 fans on my GPU


  10. Say i want to go to 3.5 or 3.6GHz using AMD Overdrive, what settings sohuld i change?
  11. AOD is great for 'test-driving' a few settings from within Windows, but your best bet is to concentrate on the Advanced Menu in the BIOS.

    Lock your PCIe speed to 100MHz - Drop your RAMs from 6.67 to 5.33 -- Drop the HT Link Speed to 8x (or, 1600MHz) -- Raise the clock to 250MHz -- Bump the NB volts a bit.

    You may then experiment with the CPU multiplier. 13x250MHz equals 3.25GHz. Test for stability and temps. You may raise the CPU mulitiplier in .5 increments up to 15 (x250MHz)

    IMPORTANT! ... read your motherboard manual for information on the BIOS settings in the Advanced Menu. Understand how to reset your CMOS. Make note of your HDD settings and boot sequence in case you have to reset your CMOS!
  12. Wisecracker said:

    AOD is great for 'test-driving' a few settings from within Windows, but your best bet is to concentrate on the Advanced Menu in the BIOS.

    Lock your PCIe speed to 100MHz - Drop your RAMs from 6.67 to 5.33 -- Drop the HT Link Speed to 8x (or, 1600MHz) -- Raise the clock to 250MHz -- Bump the NB volts a bit.

    You may then experiment with the CPU multiplier. 13x250MHz equals 3.25GHz. Test for stability and temps. You may raise the CPU mulitiplier in .5 increments up to 15 (x250MHz)

    IMPORTANT! ... read your motherboard manual for information on the BIOS settings in the Advanced Menu. Understand how to reset your CMOS. Make note of your HDD settings and boot sequence in case you have to reset your CMOS!




    I was going to use overdrive to test it the go back to defualt and go into my bios to set it all up, heres what i have in over drive:

    CPU NB multiplier: 8X

    HT ref clock: 240

    memory clock: 533

    CPU VID 1.3500

    should i proceed and see what i get? I should get 3.6GHz apparently.
  13. You should leave the NB at 10x (2000MHz). This will set the IMC/NB at 10x240MHz.

    You need to drop the HT Link Speed to 8x (or, 1600MHz).

    With the clock at 240MHz, your RAMs will be running 5.33x240MHz, or 1279MHz.
  14. Wisecracker said:

    You should leave the NB at 10x (2000MHz). This will set the IMC/NB at 10x240MHz.

    You need to drop the HT Link Speed to 8x (or, 1600MHz).

    With the clock at 240MHz, your RAMs will be running 5.33x240MHz, or 1279MHz.




    well im running the CPU at 3510MHz now and its idle temp is 15 - 17 C at 1.4V
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