X-bit labs

AMD Athlon 64 3000+ CPU Review: AMD64 to the Masses! (page 2)

Category: CPU

by Ilya Gavrichenkov

[ 12/28/2003 | 08:53 PM ]

As a result, you can come across three really different AMD Athlon 64 processor models in the today’s CPU market (I mean three models, which differ by more parameters than just the core clock frequency):

Athlon 64 3000+ features smaller 512KB L2 cache, which is also indicated by the CPU marking:

The number “4” in the third position from the end of the marking implies that the L2 cache size of the CPU with 3000+ performance rating is equal to 512KB. The Athlon 64 3200+ processor is marked with number “5” in this position.

The appearance of Athlon 64 processors with smaller amount of L2 cache memory is quite understandable. No doubt that AMD did need less expensive CPU models to be able to win a market share. And then AMD faced a question: how should they arrange the production of less expensive Athlon 64 processors at the minimal expenses? Of course, the production cost of these processors is pretty high because they are based on a rather big core. However, reducing the die size will require additional investments into the R&D (Research and Development), even if they will only have to reduce the size of the on-die L2 cache memory. Therefore it will make sense only in case the production volumes will be extremely high. At the same time large die size leads to pretty high share of defective dies, which cannot be used in Athlon 64 3200+ CPUs. Since L2 cache memory of Athlon 64 3200+ occupies more than 50% of the die, most defective dies are discarded because of the problems with the on-die cache memory. It is quite logical that disabling half of the L2 cache memory can help revive these dies. Therefore the launching of Athlon 64 3000+ with 512KB L2 cache is also a good way to get rid of some defective dies. Especially since the yields are evidently pretty low, because AMD64 architecture is still rather new.

As a result, AMD Athlon 64 3000+ is an attempt to kill two birds with one stone: the users will get low-cost processors based on AMD64 architecture, and the manufacturer will have a great opportunity to get rid of some defective dies, which cannot be used for more expensive processors, and win some additional revenue from that.