CPU fun

Shane Hathaway shane at hathawaymix.org
Tue Jun 30 13:44:52 MDT 2009

Garth Hill wrote:
> So I upgraded my BIOS yesterday willy-nilly (why oh why??) and I got a 
> nice error about my CPU being over the max 95W.  Turns out the max TDP 
> for this mobo is 95W and my processor is 125W.  So my question is this: 
> how did they work nicely together for 1 year before I flashed my BIOS?

Both the 95W and 125W processor require the same voltage.  What's 
different is their resistance to current flow.  The 125W processor can 
fall to a lower resistance, leading to more current flowing.  Wattage = 
voltage * current.

The electronics that provide power to the CPU are intended to ensure a 
particular voltage regardless of the amount of current the CPU draws. 
If the CPU draws too much current, it overdrives the power circuits, 
leading to overheating.  Overheating causes chemical changes and thus 

For this purpose, a CPU is a lot like a light bulb.  I have a lamp with 
a warning sticker that says "100 watts max".  If I install a 150 watt 
light bulb in the lamp, it will certainly work, but the risk of 
overheating would be high.

So the new BIOS now has a big warning sticker.  If you're unlucky, 
you'll fry a capacitor or chip.


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