OK, let's do some approximations here:
A P4 1.4 Williamette with RDRAM provided around the same performance as a PIII 933.
SDRAM holds back P4 performance by around 20%, so that makes it...roughly equal to a PIII 800EB.
The Celeron 2.0GHz, should be about as fast as a P4 1.5GHz with RDRAM....
I'm guessing a 20-30% performance increase, tops, if you use an SDRAM P4 board for that P4-Celeron.
You could probably get more performance for less money by putting in a $200 PIII 1.4GHz, and a $20 Upgradeware Slot-T adapter, assuming your board supports 133MHz bus speeds.
For even less money...you can get a $45 Celeron 1.1GHz and overclock it to 1466MHz on the same adapter, it will STILL outperform that Celeron 2.0GHz with SDRAM.
If you board is a Socket 370 instead of Slot-1, overclocking is a bit harder with the Socket 370 to Tualatin adapters, because they don't have onboard voltage adjustments.
And if your board doesn't support 133MHz FSB, you could use a $55 Celeron 1400, stock. This is the worst performer of the group, but still should be about equal to...that 2GHz P4 based Celeron with SDRAM.
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