AMD’s Voyage into the 64-bit Arena: x86-64 Revealed

In our "little" microprocessor community, we've got two very ambitious manufacturers, the very same names you've been hearing and debating over for the past few years, none other than AMD and Intel. Prior to AMD's release of their Athlon processor, which, for the longest time bore the codename 'K7', placing AMD's name before Intel's in a sentence was pretty much unheard of. The company had been improving their stance in the desktop microprocessor industry, but they were still more than a few steps behind Intel.

Now, just under a year after AMD's Athlon release, the company is discussing its plans to compete not only in the desktop, workstation and server markets but also in the extremely high-end enterprise market segment. You can't say that AMD hasn't come a long way from the time when their flagship processor was the K6.

Intel has been keeping themselves busy as well; in addition to maintaining their usual product lines covering the mobile, value, performance and server market segments, they are juggling the launch of the new Pentium 4 all while preparing to introduce their first major step away from the IA-32 x86 instruction set architecture (ISA) to their first 64-bit architecture, IA-64. With IA-64, Intel is promising to be free of the shackles that the x86 ISA has placed on their CPUs for over 2 decades, but in doing that, they are also flushing the idea of high performing backwards compatibility with older IA-32 applications.

If you look around the microprocessor industry, especially at those companies that already have 64-bit parts available, Intel's strategy for IA-64 isn't all that extreme. Other companies rely on emulation or even separate processors in order to maintain backwards compatibility with 32-bit applications for those customers that are not ready to completely migrate entirely to a 64-bit OS with 64-bit applications. This puts a lot of weight on the consumer (in this case, large businesses, not your usual definition of the word) to decide when moving over to a 64-bit platform would be ideal, since using this approach, you're almost never allowed to have the best of both worlds, a high performing 32-bit solution and 64-bit compatibility.

AMD saw a major flaw with this approach and felt that there should be a way for them to become a supplier of a 64-bit processor without making the consumer sacrifice 32-bit performance for that support. We're already familiar with AMD's solution to this problem as they've already announced that they'd be extending the 32-bit x86 ISA to 64-bits with what they call x86-64, but now we're finally beginning to see exactly how x86-64 will work and what it will mean for AMD's future enterprise platform, the K8, also known as SledgeHammer.