Sudden processor slow-down (Intel 6850, now only 2.4 Ghz)

[jet20]

I have an Core2Duo 6850, 3.0 Ghz, an ASUS 5PK board and DDR2 Corsair TwinX CL 4, PC6400/800 RAM.

Since the bios settings were accidentally reset a few weeks ago, the processor is only running at 2.4 Ghz anymore.

With some help from old threads in this forum, I found a too low FSB speed is the reason. The FSB should be 4*333=1333 Mhz. In fact, now it is only 4*267=1067 Mhz. Due to this, the processor now only runs at 9*267=2400 Mhz instead of 9*333=3000 Mhz. Also, I can't use the full RAM speed either, the maximum i get is 640 Mhz (2*320 Mhz) at a 12:10 Ratio, not 2*400 Mhz as would normally be possible.

Problem is, any attempts so far to get the FSB to a higher speed in the bios fail; i already set manual Ai overclocking, FSB speed and it just keeps ignoring these settings. Any idea why this happens and why the previous settings stopped working to begin with after no problems for more than 2 years?

 

[captaincranky]

Have you checked the CPU multiplier in BIOS? Sometimes that's actually what has reset.

 

[jet20]

Yes, both auto and manual settings don't change anything. The highest setting is "9" anyway, meaning 3000 Mhz cannot be reached with anything less than 333 Mhz.

 

[hellokitty[hk]]

Yes, both auto and manual settings don't change anything. The highest setting is "9" anyway, meaning 3000 Mhz cannot be reached with anything less than 333 Mhz.

Thats correct.
If you haven't already, reset again.

 

[jet20]

No effect. Any other ideas? Did anyone experience something like this before?

 

[raybay]

What are you using for your speed tests?