Nor, at least for the next few months, should users see much impact from Extended Memory 64 Technology, Intel's phrase for 64-bit extensions to its IA-32 implementation of x86 architecture -- which, the company hastens to point out, already has Intel-created enhancements like SSE3 and Hyper-Threading.

Putting a brave face on what's basically an AMD-created enhancement, Intel says the EM64T-enabled Xeon -- expected to be joined by EM64T-enabled Pentium 4 processors this fall -- gives IT managers a new workstation and server option, still positioned firmly below the Itanium family and its x86-incompatible IA-64 or EPIC architecture. The latter remains Intel's preferred platform for mission-critical enterprise work on big multiprocessor servers or other systems where scalability and floating-point performance are supreme.

Technically, EM64T keeps Intel's classic operating mode for 32-bit operating systems and applications while adding a second operating mode called IA-32e, which in turn offers two submodes -- a "compatibility mode" that lets a 64-bit OS run unmodified 32-bit software, and a "64-bit mode" that lets a 64-bit operating system run programs written specifically to access 64-bit address space. The 64-bit OS in question is likely to be Microsoft's Windows XP 64-Bit Edition for 64-Bit Extended Systems, scheduled to ship toward the end of this year, although Red Hat, SUSE, and other Linux vendors should deliver EM64T support sooner; a compatible BIOS and software drivers will be required as well as an OS.

Intel's official Q&A says that "in most cases" it should be possible to write software that runs on both EM64T and AMD64 processors, with the close similarity of the instruction-set architectures overcoming the different hardware microarchitectures involved. Naturally, the company urges developers to use Intel software tools and design specifically for Intel -- and at presstime, The Inquirer had reported that an early E7525-chipset, dual-Xeon/3.4 system failed to run the evaluation version of Win XP 64E now being used by Opteron and Athlon 64 owners, with Intel's implementation apparently optimized not just for running 64-bit code but for systems that physically have more than the 4GB of memory that's the addressing limit for 32-bit processors. Stay tuned.

Dell and HP Get On Board

Two workstation warriors wasted no time in announcing new systems based on the E7525 chipset and EM64T Xeon processors. Dell's Precision 470 (starting at $1,399) and Precision 670 (starting at $1,699) are dual-processor-capable systems available with a variety of PCI Express graphics cards, both SCSI and Serial ATA RAID storage solutions up to 800GB, and DDR-2/400 memory; the 470 has a smaller, rackable chassis while the 670 has more room for storage and peripherals expansion. They're initially available with 32-bit Windows XP Pro or 32- or 64-bit Red Hat Enterprise Linux.