Merced: The scare stories

Heard of Merced? Worried about what software won't run on it? Take a breath, relax, it ain't all bad news
Written by Jason Carter, Contributor

One of the scare stories which traditionally precede the arrival of a new processor is that existing applications will no longer run on the new platform. And so it is with Merced, otherwise known as IA-64.

Whatever software you are currently running on an IA-32 system (Pentium, PII, PIII, Xeon, Celeron, etc..) you will be able to run on systems using the Merced chip. Furthermore, if you are currently running HP-UX on a PA-RISC based system the good news is that you too will be able to run all of your existing software on systems using the Merced chip. Lynley Gwennap, vice president of the US chip analyst, Microprocessor Report, explained: "HP will have a binary translation tool (a technique built into Merced), so PA-RISC binary will execute on Merced systems."

Although HP is still working on new PA-RISC processors to be released over the next two to three years, it has publicly affirmed its commitment to shift all of its systems to IA-64 in the long term. So to recap, Merced systems will be able to run both HP-UX and Windows NT without any changes to the software. This is great news for IT managers who want a painless upgrade path, allowing them to upgrade their hardware platform without having to change also their software. However, if you want to reap the real benefits of Merced, you will eventually have to upgrade to native software.

Performance is everything

Real performance increases will only come when you are using software specifically written to take advantage of Merced's 64 bit architecture. Think of it as upgrading your old cassette player to a brand new hi-fi stack-system - the new system can still play your old tapes but to get the best from the system you need to play CDs on it.

Microsoft is currently working on a 64 bit version of Windows NT, which it claims will be ready by the time Merced systems start shipping in bulk. It will also support Compaq's Alpha processor. Microsoft stresses that this will be complementary to 32 bit Windows and not a replacement for it. Likewise, HP is also working on a version of HP-UX, which is already a stable 64 bit operating system, fully optimised to take advantage of Merced. A host of independent software vendors have also announced support for IA-64.

This won't really involve much work for most software manufacturers, for the most part all they will really need to do is run the source code of their existing applications through the new software compilers which create code capable of exploiting IA-64s various performance enhancing features. And for all the tree hugging hippies out there, don't worry, a full IA-64 port of Linux is on the way from VA Research.

The bottom line

If you're currently running IA-32 or PA-RISC systems, upgrading to Merced will be fairly simple because you can simply continue using your current software. Once the servers are in place, you can worry about upgrading the software at leisure. Migrating from other platforms to IA-64 might not be so straightforward, but then, life is never easy when you're migrating to new hardware and software platforms.

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