Oh I'm not saying that it doesn't work... just that it's thermal sensitivity
may be off...
As for the 1.3Ghz Duron... my typo (now fixed), I meant the 1.3Ghz Athlon (and Palomino's) have a higher Vcore (1.75v) than the later T'bred-Barton-Sempron processors, wattage output of the '
C' class 1.33Ghz Athlons (*266fsb) was around
75w... not too sure about the earlier series

In your BIOS, are you selecting the 'user define feature' before attempting to tweak settings?
Things also worth checking...
* Is your heatsink seated properly?
* did you use enough/too much thermal paste?
* is the heatsink rated for the Athlon ie. (Morgan core) Duron 1.3 is rated @
60w approx.
* is the fan CFM sufficient?
* does the case have adequate ventilation/fans? (perhaps run it with case open to test)
My Athlon 1100 @ 1210Mhz idles around 42c & heats up to 48-52c running F@H 24/7 (it's summer here)
EDIT:Here's what I mean about heatsinks... the larger aluminium unit on the left is for the early Athlon class processors, the remaining two were purchased with Duron 800/750's respectively... personally whoever fitted the extreme right heatsink to a
1.75v processor was preoccupied only with budget, I wouldn't even use 'that' on my K62 processors
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