*lol*
The intel Celeron is known to have by far the worst IPC ever observed in any x86 CPU design to date
The AMD Duron, however, still packs its 128k of L1 Cache, plus the exclusive 64k L2 Cache, bundeled with the far superior FPU of the Athlon family.
Add SSE to it, with a fairly low specific power consumption (Celerons have almost the same TDP than Pentium4's!), and you have a really decent CPU in the very low price region.
At 1600MHz, it is measured almost persistently faster than a Celeron 2600MHz (!)
And I don't know where you guys live, but here, the Celeron 2600Mhz is
at least 2x (rather 2.5-3x) the price of a Duron 1600Mhz
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All in all, that's why tech-experienced Users normally won't even touch a Celeron.
Against the AMD Duron, there is practically only one competitor :
...the AMD AthlonXP
To make a long story short :
If you buy a Celeron, you either want to spend 2-3x the money on eqal or less performance, or
really have an odd reason to do so (e.g. keep an existing intel platform at all costs).