In a bold attempt to leapfrog Intel Corp., Advanced Micro Devices Inc. last week introduced a family of 64-bit processors for mainstream PCs that it hopes will mark the beginning of the end for 32-bit computing.
To kick off its crusade, AMD introduced three Athlon64 processors targeting desktops, mobile systems, and high-end game machines. The line comes five months after AMD introduced Opteron, a 64-bit processor for servers and workstations. Opteron and Athlon64 are based on the same micro-architecture, which includes an on-chip memory controller and sophisticated out-of-order execution and branch prediction capabilities.
Though 32-bit computing is unlikely to disappear soon, AMD believes that if 64-bit processors are available, the software will soon follow. A number of software developers involved in the Athlon-64 launch expressed interest in moving to 64-bit. Among them was Microsoft Corp., which is expected to announce a 64-bit version of Windows next year.
A major advantage of moving to a 64-bit bus, according to AMD, is that the processor can address more than 4Gbytes of memory--beyond the capability of 32-bit systems--to support realistic computer graphics and transmission of high-bandwidth data, such as video over wireless networks.
AMD is betting that PC games will be among the first applications to make the switch. Since it launched its first 32-bit Athlon, the company said it has had considerable success wooing game enthusiasts, and it sees Athlon64 as a way to build on that momentum.
To drive home this point, AMD has introduced a premium line of 64-bit processors under the AthlonFX brand, which includes a large on-die cache and 128-bit interface to external DDR memory, features that should boost bandwidth to main memory while reducing latency.
The transition to 64-bit computing could depend largely on trends in memory technology. Today the average desktop system has about 512Mbytes of DRAM, but to get the most out of 64-bit processors that would need to increase to 2Gbytes or more. Fred Weber, vice president and chief technology officer for AMD, Sunnyvale, Calif., said he is confident that memory prices will continue to decline at a rate that will fuel more memory usage.
Still, 64-bit will be overkill for many office productivity tools, which could make it a tougher sell for business users and IT managers. Weber acknowledged that many applications won't need 64-bit capability, but added that market trends could bolster the case for more computing power. For instance, the replacement cycle for PCs has increased to four years, which would give IT managers an incentive to switch to 64-bit systems earlier rather than later, he said.
Moreover, AMD stressed that having 64-bit capability won't come at the expense of 32-bit performance. The company claims that its FX-51, for example, can outperform a 3.2GHz Pentium 4 by 10% to 20%. This claim may have to be revisited when Intel introduces Prescott, which will be built on 90nm process technology and feature an enhanced P4 architecture. AMD's Athlon64 is made using 130nm design rules.
Despite an implied performance advantage at 90nm, Rick Wittington, an analyst at American Technology Research, questioned in a recent report whether Intel can reduce Prescott's power and heat to acceptable levels and still hit performance targets.
"The conclusion is that AMD looks increasingly likely to hit the ground running in Q4 and 2004 with its next- generation X86s, at a time when Intel is not able to counter quickly," Whittington said.