Intel's virtually there with Montecito

Intel engineers and planners released a few more details about the forthcoming dual-core Itanium chip code-named Montecito on Thursday at the Intel Developer Forum. Focusing on virtualisation, the process where one chip can pretend to be multiple independent systems, strategic planner Nima Homayoun said: "It's all about how to configure infrastructure, how to grow things. Virtualisation breaks physical units down into smaller, more manageable pieces."

Intel previously demonstrated its virtualisation technology, code-named Vanderpool, running on an as-yet unnamed 32-bit chip. The Itanium version, called Silvervale, is the first one to be described in any depth. "It's a combination of hardware and the processor abstraction layer [internal software that configures and controls how the processor works with external software]," said Paul Shim, computer architecture specialist. "Existing operating systems and applications software won't need to be modified in any way."

In virtual systems, operating systems and applications software think they're running directly on a physical computer. Instead, the real physical computer is maintaining a number of virtual copies of itself, each of which looks to software like it's the only one. These virtual machines are handled by a virtual machine manager, VMM, which arbitrates between any conflicting requests that may arise when two VMs try and access the same physical resource.

Previously, virtualisation software such as VMWare had to dynamically scan applications and OS software for instructions that could not easily be handled, and then patch them out with special code. This will not now be necessary, as Silvervale will spot these when they try and run and will pass them back to the virtualisation software to be handled on the fly. There were also considerable performance penalties when a VMM had to switch between different environments; these have been considerably lightened by Silvervale, which handles this information in a single data structure per virtual machine that it shares with the VMM. Similarly, Silvervale can be configured so that when there's no danger of a physical resource being fought over it can be handed over with minimal further management, improving performance further.

"This will be a stable platform across processor generations," said Shim. "It will help consolidate legacy applications and operating systems, improve testing and reliability of new developments, and won't need lengthy application pre-qualification".

Both HP and Hitachi were quoted in the presentation as approving Silvervale. "HP is excited about working with Intel to incorporate the latest virtualisation features of the Itanium processors into products such as the recently announced HP Integrity Virtual Machines," Nick van der Zweep, HP's director of virtualisation and utility computing was reported as saying.