As soon as Sempron will hit the market, the lower and middle class AthlonXP models will immediately be phased out. The first victims of AMD's new course will be all models up to 2500+. The 2600+ and 2700+ chips will ship last in the third week of August according to a recent AMD roadmap. All the faster models will remain available till the end of Q3 and will be given a quick death then.
Barton Was Too Big
Some of you might wonder why AMD didn't pick the best AthlonXP core they had available. The reason is simple: While Thoroughbred-B has a die size of 84 mm², Barton already requires 101 mm² - which is approximately 20% more. In addition, Barton's heat dissipation of 74.3 W maximum is around 10% higher than the 68.3 W of Thoroughbred-B. While this may not sound like a great deal, it will contribute to keep cooling costs as low as possible.
Thoroughbred-B's die size is 20% smaller than Barton's - that is quite a strong argument in favor of the first.
A Platform War: AMD Vs. Intel
While Socket A might still be selling extremely well by offering an excellent price/performance ratio, which could easily change at the end of this year already. Although there are fast chipsets like the NVIDIA nForce2 Ultra 400 Gb and VIA's KT880 - both support Serial ATA, NVIDIA even comes with native GbE support - they will soon be out featured by Intel's latest 900 chipset series.
915G, paired with DDR2 memory and almost 3 GHz will be able to outperform nForce2 IGP and Sempron 2800+. Also, ATI is expected to launch the RS400 P4 chipset later this year - likely it will be able to beat Intel's 915G. The 915GV will be available as a chipset version without x16 PCI Express slot for upgrading dedicated graphics. In addition, the 910GL chipset without DDR2 support will be waiting for the lowest-cost market. Both will be priced at more or less a threshold that big buyers are still willing to pay for 'Intel inside'. In addition to that, Intel plans to decrease the chipset prices by $1 (915P and G) respectively $2 with the introduction of the LGA 775 Celeron D.