While Intel has a strong and clear trend to enlarge caches in its NetBurst processors, such as Intel Pentium 4 and Xeon, its arch-rival Advanced Micro Devices seems to bet on its Athlon 64 central processing units with 512KB L2 cache. The company will reveal its 90nm products later this year, but those will not include any improvements except clock-speed potential.
To tell you the truth, 512KB is a magic number for level-two cache of AMD processors. The company recommended to install 512KB of L2 on mainboards intended for AMD K6 and K6-2 processors. First AMD Athlon processors for slot A also had 512KB of L2 cache, just like the last and final seventh-generation chips for Socket A with Barton core. Even though the initial AMD Athlon 64 CPUs pack 1MB of L2, we see an obvious tendency towards 512KB L2 for the majority of desktop 64-bit processors to come in the second half of 2004 and the first half of 2005.
As previously revealed, starting from late March 2004 AMD will do its best to popularize its Socket 939 platform and processors. 939-pin chips are attractive for AMD, as they only incorporate just 512KB of L2 cache, only half the L2 size of currently available AMD Athlon 64 3200+ and 3400+ chips. Switchover to 939-pin packaging is not the only measure to sweep away desktop AMD64 chips with 1MB of L2 – starting from Q2 2004 the Sunnyvale, California-based semiconductor maker will add 754-pin SKUs with 512KB of cache, but higher clock-speeds, into the lineup. Smaller cache means lower transistor count which may potentially mean higher yields and/or improved clock-speeds.
With dual-channel memory controller AMD Athlon 64 processors in 939-pin packaging will most likely to offer the same performance as Athlon 64 chips in 754-pin packaging with 1MB L2 and single-channel DDR SDRAM controller. Higher core-clock is also likely to lower the impact of smaller cache on performance in real-world apps.
Given that Athlon 64 3700+ clocked at 2.40GHz, the chip very likely to become the last option for Socket 754 platform, is the fastest processor made using 0.13 micron SOI technology, the main target for AMD is to substantially improve yields of its products, as further core-speed improvement beyond 2.40GHz may be not be that trivial. Nevertheless, it looks like core-speed bumps cost AMD less than a megabyte of secondary-level cache memory.
In total, there will be 6 AMD64 processors for desktops with 512KB of L2 available this year:
- AMD Athlon 64 3000+, 2.00GHz, 512KB L2, 754-pin.
- AMD Athlon 64 3200+, 2.20GHz, 512KB L2, 754-pin.
- AMD Athlon 64 3400+, 2.40GHz, 512KB L2, 754-pin.
- AMD Athlon 64 3400+, 2.20GHz, 512KB L2, 939-pin.
- AMD Athlon 64 3700+, 2.40GHz, 512KB L2, 939-pin.
- AMD Athlon 64 4000+, 2.60GHz, 512KB L2, 939-pin.
Note that AMD Athlon 3700+ will exist in two versions on the market: one will be based on
It is estimated that AMD will supply roughly 2.40 million of Socket 939 64-bit AMD Athlon 64 processors this year. At the same time, the firm is likely to ship around 3.50 million of Socket 754 AMD64 chips. Especially keeping in mind that Socket 754 architecture is definitely somewhat cheaper than Socket 939, such estimations look pretty reasonable.
Product roadmap for AMD64 microprocessors for the second half of 2005 is not yet finalized. We do know that there is a 90nm SOI successor for high-end parts, such as AMD Athlon 64 FX and AMD Opteron, code-named