Conclusion
In a direct clock rate comparison (clock-by-clock), the Tualatin 512 kB has on its plus side considerable performance advantages in many categories over 256 kB CPUs like the Pentium III Coppermine, the Tualatin 256 kB or the Athlon. Except in floating point performance, where no one can hold a candle to the Athlon, the architecture of the PIII Tualatin would be quite attractive to the standard user. Moreover, the switch in the manufacturing process from 0.18 to 0.13 microns would enable significantly higher clock speeds than the feeble 1266 MHz.
But Intel's priority is to avoid leaving its self-declared favorite, the "Pentium 4", high and dry. In the face of policy-bound price distortions, many home users are keeping away from the Pentium III-S 1266 (512 kB). All other candidates, whether the Athlon or the "lesser" Pentium IIIs, offer definitively better cost effectiveness. And there's more: Intel wants to stop at 1266 MHz! With the Tualatin's 0.13 microns, Intel would not have had any problem instigating a fresh clock rate war with the Athlon (0.18 microns). But Intel won't saw off the branch it is sitting on. The Pentium 4, whose architecture is designed for clock rates that are well under the 3 GHz brand, is the declared flagship for the future.
In the short run, Intel still makes upgrading a farce: because of altered pins and a new bus protocol, a new "Tualatin-compatible" motherboard must still be purchased despite having the same socket 370. The current situation makes the PIII Tualatin with 512 kB attractive only for certain server applications, especially if the procurement costs are less important.
One last thing to consider: only slight changes from the Coppermine were made to the architecture. Research and development costs have long since been recovered with the Pentium III. The return on investment was therefore realized a long time ago. Only the cache memory was increased. But you can do that simply by clicking into the right software library in the design department. The miniaturization to 0.13 microns even enables a higher yield rate. Although these would be good conditions for lower prices, Intel is playing the martyr with its Pentium III-S 1.26 GHz. It's still a mystery to us why Intel even put this CPU on the market.
