Intel is due to release its first 32/64bit hybrid chips in the next few months but experts believe that rival AMD's system architecture could in some cases still be a better choice for volume servers.

At the recent Intel Developer Forum in San Francisco, Dell, IBM and HP all said they will make servers based on Intel's new Clackamas Technology (CT) that will work on reworked Xeon and Pentium 4 chips. Intel is well-entrenched in servers and has a long history of catching up with the advances of its smaller rival.

However, AMD's Opteron chip has a year's headstart, so this time the pattern might be broken. "Server tasks are highly conditional but there's no question Opteron has a superior system architecture in terms of scalability and main memory bandwidth," said Peter Glaskowsky, editor-in-chief of Microprocessor Report.

Against that, Glaskowsky noted that Intel's new Prescott core and the Hyper-Threading ability to execute threads in parallel could help Intel. "There are dual-processor Opteron servers that can beat four-way Xeons and, in certain unusual conditions, dual-Xeons that can beat four-processor Opterons. It's too early to [say which is superior] until we see the benchmarks," Glaskowsky said.

Richard Baker, European marketing manager at AMD, said, "Intel is still taking an old technology and applying the extensions to an old pipeline. They don't have our HyperTransport [chip-to-chip communications links] or on-board memory controllers so it will be interesting to see the performance benchmarks."

Rakesh Kumar of analyst firm Meta Group, commented, "The technical superiority of Opteron is always going to be there but that's balanced by Intel's huge muscle in manufacturing and the fact it can afford to sustain low [profit] margins."

AMD last week added HP to IBM and Sun in its roster of firms basing products on Opteron. HP plans to release an Opteron-based ProLiant server this month and though HP will also support CT, the move is significant in that HP was Intel's design partner on the 64bit Itanium, and intends to port its collection of enterprise operating systems to Itanium.

Intel will continue to push Itanium as a 64bit powerhouse that is ideal for very high-end servers, but the trend for scale-out architectures for server clusters and computer grids could limit its progress. In a posting last week, Linux founder Linus Torvalds described Itanium as "some other 64bit architecture nobody wanted to use".

However, both the Microprocessor Report's Glaskowsky and analyst firm Gartner suggest demand for Itanium will not be affected by CT in the short term.

"Server processors of this class have system implementation requirements that extend well beyond 64bit addressing," Gartner noted. These requirements include multiprocessor scalability, data integrity and a long mean time to failure.