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Help Overclocking Athlon II x4 635

Hey folks,

I recently picked up an athlon 635 processor. I bought it with the hopes of getting a good overclock on it.

However, I cannot get it above 3.0ghz with out the computer shutting off.

This is my setup:

Asus M4A78-EM (780g/700sb)
3gb OCZ platinum ddr2 800 (2x 1gb, 2x 512)
Sapphire 4670 1gb
400w xion PSU
Win 7 home



I ve been using AMD overdrive to raise the bus speeds and increase voltage, but it hasnt worked out well.

How important are memory timings when over clocking? Also, the PSU is a cheap one, could that be the source?


The operating temps of the processor/board are far from overheating. The processor hits 45 degrees under load.

Any suggestions?
10 answers Last reply Best Answer
More about help overclocking athlon
  1. Did you lower the RAM multiplier, if not its most likely the RAM cannot handle the speed.
  2. Best answer
    Hi docfeelgood and welcome to Tom's forum.

    1- Don't use AMD overdriver to OC.
    2- Always OC from the BIOS.
    3- The 635 is a locked CPU that means that u can't change the multiplier CPU to rise or drop the speed of it in that case u need OC with the FSB (bus speed as u call it) but rising the FSB u also change the RAM speed because both are linked. The 1st thing that u need to do is slow down the RAM speed to 667 after that u can start to rise the FSB.

    Don't forget test the stability of the rig with prim95 3 hours, OCCT 2 hours or LinX 1 hour because that u can boot or log in doesn't mean that the rig is stable.
  3. Ok, ill try slowing the ram down.

    Would that counteract the benefits of increasing the CPU frequency?

    Ill try it tonight. I would like the processor to run comfortably at 3.4 if possible.
  4. Also, I should mention, Ive tried increasing the bus/ht link speed in the bios, but for some reason it doesnt reflect when i boot up. It still shows that its running at stock speeds
  5. HT link also rise with the FSB but the HT link can't be more that the NB frequency or u could have problems.

    The recommended speed for the HT is 2000MHz.
  6. Sweet. I followed your suggestions and all was well. 2hrs on prime 95 and all is stable.


  7. Also.. what a wicked processor. I picked it up for 99$ a couple months ago. I have never seen a 100$ processor go so far in terms of price/performance.
  8. Well bro is the AMD price/performance. Enjoy it ;)
  9. I should also add, the correct voltage is 1.41v, not the 1.37 as posted above. It was a little bit unstable @ the stock voltage.
  10. Best answer selected by docfeelgood.
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