Finding the Philosopher's Stone
AMD has long been searching for the ultimate weapon to fight Intel with. The company has found it – the AMD64 technology. It is the first revolutionary extension to the x86 architecture since the 386 processor and transition to 32-bit calculations. By the way, you may recall that the last transition took as long as 10 years, so we shouldn’t wait for the whole industry to be hasty about recompiling software for the 64 bits – many programs just don’t need that. Anyway, no one will be worse off for the change, while certain categories of tasks have long been in need of a 64-bit architecture. Well, software developers now have this option. It is even more important for AMD that the AMD64 technology is purely of their own development – a hefty plus to the corporation image.
We can also recall one evolutionary extension to the x86 architecture, the MMX technology. All later SIMD extensions – 3DNow!, SSE, 3DNow! Enhanced, SSE2, 3DNow Professional, SSE3 – are just sequels to the original idea of SIMD instructions, for other data types.
We can already speak about the industry’s having accepted the AMD64 technology. Right now (i.e., about a year after the official arrival of AMD64), there are over 1000 companies cooperating with AMD on hardware and software projects, starring such giants as IBM, HP, Sun and prominent software developers. Moreover, Microsoft has already offered its Windows XP 64 for Athlon 64 and Opteron for users to taste. You don’t have a great choice of programs to run in this OS yet (besides 32-bit applications, of course), but the release of the operating system is a signal for many software developers to start – no one will write programs for a non-existing OS. Thus, again, AMD64 has found its place under the sun. There’s now no question about if it is going to become a mass technology and the main direction of the evolution of the x86 architecture (by the way, this situation has no precedents in the past) as Microsoft has supported it. On the other hand, this technology has been invented and promoted by a firm that has about one fifth of the processor market, so there are some “nuances” possible.
Anyway, the 64 bits is a powerful weapon in the hands of the marketing men and AMD will base its advertising and marketing campaigns around it. AMD will probably draw the sword when it starts promoting its Athlon 64 architecture for the mass user – so far, the presence of these processors has only been felt in the sector of top-end systems. This will coincide with the announcement of the Socket 939 platform (scheduled for April), which is going to become the mainstream platform with AMD64 support. This platform will remain a mass one for several years – it’s hard to tell how long as it depends on too many factors.
Intel also realizes the appeal of the “64 bit for everyone” slogan. Against its own will, with words like “it’s not very necessary, but if people demand – here it is”, the corporation announced that it would ship Xeon processors with CT technology in the second half of the year (the technology will probably be named EM64T – Extended Memory 64 Technology). This technology actually copies AMD64 without some additional features like 3DNow! Moreover, it won’t support the so-called NX bit (the abbreviation for “No eXecute”), which allows for hardware protection against such a common plague of 32-bit OSes as the “buffer overrun” error. Intel included something of its own, the SSE3 instruction set, but I think they’d be better off keeping full compatibility with the AMD64, rather than trying to put a good face on things. Moreover, SSE3 is not a wide step onwards as SSE2 was: in fact, SSE2 allowed working without the x87 coprocessor, which is difficult to wield efficiently, while SSE3 only adds a few previously omitted instructions.
One of the reasons for this incomplete support may root in the fact that this NX bit is supported by the hi-end Itanium platform and Intel wants to distance the two platforms from each other.
By the way, the Xeon 3.6GHz with 1MB L2 cache, the first processor to support EM64 technology, is rumored to come out sooner than anticipated. This fact is a signal that Intel is worrying about its share of the server market where the Opteron now shows very good speed characteristics.