Forget the combative hype from arch-rivals Advanced Micro Devices Inc. and Intel Corp. over their upcoming 64-bit processors. The real battle begins next year when AMD's Sledgehammer enters production against Intel's Itanium, and the market weighs in.
AMD this week released detailed Sledgehammer specs for software developers, two weeks before Intel is slated to unload its own technical data at the Intel Developer Forum in San Jose. AMD again touted its "bottom-up" strategy of expanding its 32-bit Athlon core by adding 64-bit capability.
Both Sledgehammer and Itanium run 32-bit software seamlessly in hardware, using separate compatibility modes. The difference is, AMD is engaged in a more evolutionary and inclusive migration of its X86 architecture to 64-bit processing, while Intel is optimizing its 64-bit mode while omitting some top-of-the-line features of the 32-bit Pentium 4, said Nathan Brookwood, an analyst at Insight64, Saratoga, Calif.
AMD and Intel executives agreed with Brookwood's assessment. Customers needing maximum 32-bit performance will use the next-generation Pentium 4, said Jason Waxman, an Intel Itanium design engineer. Even so, he said, Itanium and its 64-bit successor, McKinley, will offer very high 32-bit performance. "These chips just won't have some of the very enhanced new features of Pentium 4, such as out-of-order execution that isn't built into the
32-bit compatibility mode," Waxman said.
The issue of 32-bit compatibility is important for AMD and Intel, particularly in the server market, which has a large number of 32-bit legacy applications. Of course, the AMD/Intel shootout is taking place as both companies try to drive a Windows-based platform against a firmly established Unix market already served by the likes of Sun Microsystems' UltraSparc,
Compaq Computer's Alpha, MIPS, and IBM's RISC MPUs. AMD and Intel claim their chips will be less expensive than a RISC alternative, and will tap into the vast base of X86 users looking to upgrade to 64 bits. The exploding network-server market, a heavy user of X86 processors, is another prime target, Waxman said.
"It will take about a year for the market to determine [which] strategy is right," Brookwood said. "If AMD can deliver Sledgehammer with a 64-bit performance equal to Intel's, their higher 32-bit performance could be a real winner." Many applications, such as network servers and mainstream engineering and design computers, will continue to have 32-bit programs that could capitalize on Sledgehammer capacity while migrating to 64-bit programs, he said.
"If AMD can't match Intel in 64-bit processing, then its 32-bit advantage won't matter," he added.
The differing design techniques have been defended by AMD and Intel. In releasing the Sledgehammer specs, AMD said the new processor allows application-software developers to write 64-bit code to upgrade existing programs without emulation or recompiling, said Steve Polzin, an AMD system architect.
Intel said the Itanium and McKinley will run 32- and 64-bit programs seamlessly on the same chip hardware, using a bit switch to send 32-bit instructions to on-chip registers designed to operate in a compatibility mode. Waxman said there is no loss of performance when operating in the native 32-bit mode.