Intel is to introduce multithreading and 24Mbyte on-chip caches to its Itanium 2 processor family.
Itanium's first multicore processor, codenamed Montecito, will also have multithreading when it is released in 2005, said Ajay Malhotra, the director of enterprise marketing and planning for Intel's Enterprise Systems group. The chip will also have 24Mbytes of on-chip cache, much more than the 9Mbytes available in Intel's Madison processors.
Multithreading allows a single processor to operate like multiple processors, so with multithreading, a dual-core Montecito would appear to the operating system to have at least four processors.
Intel's follow-up to Montecito, the 8-core Tanglewood processor being developed by a team of former Alpha processor developers, will also be multithreaded, but it may take a different approach to the problem. Malhotra said it will have seven times the performance of Madison Itanium 2 processors, an improvement that will primarily be driven by how Intel implements multithreading and how the company manages to link Tanglewood's cores together.
Multithreading is particularly difficult to bring to the Itanium "in order" processor architecture, said Nathan Brookwood, an analyst with industry research firm Insight 64.
"I'm amazed that they can do it because the secret for Itanium performance is very sophisticated compilers and multithreading is not the sort of stuff that compilers can accommodate."
Intel's move to 24Mbytes of on-chip cache is less remarkable, he added. "They're taking two Madison 9Mbytes and smashing them together on a chip, so you knew it was going to be at least 18Mbytes."
Robert McMillan writes for IDG News Service