Tukwila (processor)

Lore & Background

Tukwila was code-named after the city of Tukwila, Washington, and was originally known as Tanglewood—a name also used by a music festival—until Intel renamed the project in late 2003. The engineers working on Tukwila were from the DEC Alpha project, specifically those who had worked on the Alpha 21464 (EV8), which was focused on SMT. The processor's transistor budget breaks down as follows: core logic 430 million, system interface 157 million, L3 cache 1,420 million, I/O logic 39 million, for a chip total of 2.046 billion.

Tukwila was originally stated to bring socket compatibility between Intel's Xeon and Itanium processors through a new interconnect called Intel QuickPath Interconnect (formerly Common System Interface or CSI). This was intended to reduce product development costs by allowing greater reuse of components and manufacturing processes. Tukwila is reported to have four 'full' QuickPath links and two 'half' links. However, the released Itanium 9300-series processors use a separate socket, LGA 1248, which is incompatible with Xeon processors and motherboards. The first Xeon processor to feature QuickPath, code-named Whitefield, suffered significant project delays and was cancelled; the first Xeon MP processor to feature QuickPath was Beckton.

Reader's Guide

Tukwila's significance lies in its role as a milestone in transistor integration, being the first processor to exceed 2 billion transistors on a single die. This achievement was driven largely by its large L3 cache, which accounted for 1.42 billion of those transistors. The processor also marked a technical lineage from the DEC Alpha project, as its engineers had worked on the Alpha 21464 (EV8), a design focused on SMT—a technique Tukwila itself employed. The attempt to unify Xeon and Itanium sockets via QuickPath Interconnect was a notable strategic endeavor, but it ultimately did not materialize for Tukwila; the released processors used an incompatible LGA 1248 socket. This left the Itanium and Xeon lines on separate sockets, despite the original goal of reducing costs through shared components. Tukwila's successor, code-named Poulson, was initially slated for a Q4 2009 release and said to have over four cores, most likely eight. In 2009, an Intel representative stated that Intel would maintain a two-year development cycle for Itanium, implying Poulson would be released in Q1 2012.

Did You Know?

• Tukwila was originally code-named Tanglewood, after the Tanglewood music festival, before Intel renamed it in late 2003.
• Tukwila's die size is 21.5 × 32.5 mm, or 698.75 mm².