UPDATE: Removing the initially mentioned May/Q2 2004 timeframe for the announcement of the AMD Athlon FX-55 microprocessor due to updates from the original source. Setting mid/late-Q3 2004 date for the part based on information from an unoffocial source.

Advanced Micro Devices is grouping its forces to attack its arch-rival Intel Corporation with new and powerful processors about a quarter earlier than it originally planned.

AnandTech reports that according to a recent roadmap, AMD Athlon 64 FX-53 clocked at 2.40GHz processors will come out this month, while the Athlon 64 FX-55 chip with 2.60GHz frequency will show up as early as in mid/late-Q3. The latter microprocessor was originally scheduled for Q4 2004, but is reported to be unleashed earlier.

AMD Athlon FX microprocessors are positioned as top of the line offerings from Advanced Micro Devices. While the architecture of the Athlon 64 FX is the same compared to the Athlon 64, e.g. the chips can execute the same software, including 64-bit software, the chips feature large 1MB level-two cache as well as dual-channel memory controller, bringing some additional speed bumps for the chips that cost above $700.

AMD Athlon 64 FX microprocessors are going to be available in two types of packages: 940-pin and 939-pin. The former requires registered memory modules, while the latter is expected to work with typical unbuffered DIMMs. AMD Athlon 64 processors are going to exist in two versions as well: Socket 939 and Socket 754. Chips in 939-pin packaging feature dual-channel memory controller, but only 512KB of L2 cache, processors in 754-pin packaging feature single-channel memory controller and 512KB or 1MB L2 cache.

Apparently, Athlon 64 3700+ (2.40GHz) for Socket 939 has been renamed to Athlon 64 3800+, while the Athlon 64 3400+ (2.20GHz) for Socket 939 is now called Athlon 64 3500+. Both 939-pin chips will emerge in May. Athlon 64 3700+ (1MB L2, single-channel memory controller) for Socket 754 platform will be available in April. Additionally, we may see the 754-pin Athlon 64 2800+ chip later in the quarter.

The forthcoming AMD Athlon 64 FX-55 (2.60GHz) and AMD Athlon 64 3800+ (2.40GHz) will be AMD’s top offerings this year, according to the report.  The AMD Athlon 64 4000+ and AMD Athlon 64 4200+ are moved into the 2005. While the both top offerings from AMD will certainly be able to successfully compete against the Intel Pentium 4 3.80GHz, will they be as fast as the Pentium 4 4.00GHz in the fourth quarter of the year?

AMD did not comment on the story. Information obtained from unofficial sources as well as from roadmaps is usually subject to change, as the companies are reshuffling their plans quite often.