The New NewCastle Core
Switching to Socket 939, AMD also transfers the Athlon 64 family to the new processor core, known under the NewCastle codename. Compared to the ordinary ClawHammer, this core has a twice-smaller L2 cache (512KB). The NewCastle core has already been used in some modifications of the Athlon 64 for Socket 754, but now the ClawHammer core (1MB L2 cache) will only be used in expensive Athlon 64 FX family processors. The purpose of this transformation is evidently in making the Athlon 64 cheaper to manufacture.
Really, the ClawHammer core with its 1MB of L2 cache has a die size of about 193 sq. mm. The reduction of the amount of L2 cache memory allows reducing the die size to 144 sq. mm.
By using the Wafer utility written by Rick C. Hodgin, we can estimate the number of dies in one 200mm wafer like those used at the Dresden Fab30 which is now producing Athlon 64 processors.
As you see, one 200mm wafer contains either 144 ClawHammer cores with 1MB L2 cache, or 194 NewCastle cores with 512KB L2 cache. Thus, the use of the NewCastle core allows increasing the yield of processor cores by 34% from one wafer! This means that the manufacturing cost of one NewCastle core is about 25% lower than that of a ClawHammer core. In other words, if the manufacturing cost of a ClawHammer processor is estimated at $100, the new NewCastle-core processor will cost AMD about $75. On the one hand, AMD will increase the profitability of its Athlon 64 production, and on the other hand, this may become a step to an invasion of the Athlon 64 into mainstream and low-end market sectors, because AMD can make cheaper modifications of its 64-bit processor. According to some sources, we may soon see an Athlon 64 with a PR of 2600+, selling for less than $150.
Well, notwithstanding the use of the cheaper NewCastle core in Socket 939 processors, their price will be very high initially. For example, the official price of the Athlon 64 3500+ is $500, while the Athlon 64 3800+ is evaluated at $720. Such high prices are not because of manufacturing costs, but rather because AMD thinks that Intel offers no worthy alternatives today. That’s why the pricing of the new Athlon 64 in the Socket 939 form-factor will become more modest with time, but only after Intel has introduced new and faster processors.
Another fact needs emphasizing: AMD doesn’t seem willing to exert any effort in promoting Socket 939 systems for the time being. At first, the production volume of such processors will be rather small, while junior CPU models won’t come out for the new socket. This situation will only start changing in the fourth quarter when new chipsets and new mainboards will bring PCI Express and DDR500 SDRAM to the Socket 939 platform.