Intel offers the Itanium 2 9100-series in five different models, as long as its 1.66 GHz or 1.6 GHz. However, Intel offers the Itanium 2 9100-series in different iL3 cache sizes to designate different model numbers. Three iL3 cache sizes are available – 24MB, 18MB and 8MB. Intel also designates Itanium 2 9100-series processors with an M suffix for 667 MHz front-side bus and N suffix for 533/400 MHz front-side buses. The ugly duckling of the Itanium 2 9100-series lineup is the 9120N. This model is the only Itanium 2 9100-series without a 1.66/1.60 GHz clock speed. It has a lower 1.42 GHz clock speed with a 533/400 MHz front-side bus. The Itanium 2 9120N is the only dual-core model with a 12MB iL3 cache. Despite the lower clock speed, the Itanium 2 9120N has the same 104-watt TDP as the higher-clocked models.
All dual-core Itanium 2 models, with the exception of the 9130M, can execute up to four threads.
Intel also has one single-core Itanium 2 9100-series in the lineup. The Itanium 2 9110N has a 1.60 GHz clock speed and 12MB of iL3 cache. It also has a 533/400 MHz front-side bus. The single-core Itanium 2 has a 75-watt TDP rating. Intel prices the Itanium 2 9110N at $696. Intel does not have any new chipsets in the pipeline for the Itanium 2 9100-series. The Itanium 2 9100-series will continue to use the Intel 8870 with its DDR-200 memory controller. The Intel E8870 only supports 400 MHz front-side bus processors. Third-party chipsets are required to take advantage of faster 667 MHz and 533 MHz front-side buses. Intel’s next Itanium, the follow up to Montvale, will not arrive until 2H’08. Tukwila will be a quad-core processor with Intel’s QuickPath, formerly known as common system interface, technology. Tukwila will have a 65nm fabrication process and will drop into a new Boxboro MC platform. Expect Intel to debut the Itanium 2 9100-series next quarter, after the current Itanium 2 9000-series is EOL in August.
quote: I assume there is the big factor that a cluster of servers would use more power and produce more heat than a multi-processor Itanium system. I don't know what the breakdown of costs are, maybe it's cheaper to do a multi-processor Itanium than an equivalent multi-processor Opteron or Xeon system, when you hit a certain number of CPUs allowed