UltraSPARC T1

Sun Microsystems' UltraSPARC T1 microprocessor, known until its 14 November 2005 announcement by its development codename "Niagara", is a multithreading, multicore CPU. Designed to lower the energy consumption of server computers, the CPU typically uses 72 W of power at 1.4 GHz.

Afara Websystems pioneered a radical thread-heavy SPARC design. The company was purchased by Sun, and the intellectual property became the foundation of the CoolThreads line of processors, starting with the T1. The T1 is a new-from-the-ground-up SPARC microprocessor implementation that conforms to the UltraSPARC Architecture 2005 specification and executes the full SPARC V9 instruction set. Sun has produced two previous multicore processors (UltraSPARC IV and IV+), but UltraSPARC T1 was its first microprocessor that is both multicore and multithreaded. Security was built-in from the very first release on silicon, with hardware cryptographic units in the T1, unlike general purpose processor from competing vendors of the time. The processor is available with four, six or eight CPU cores, each core able to handle four threads concurrently. Thus, the processor is capable of processing up to 32 threads concurrently.

The UltraSPARC T1 can be partitioned in a similar way to high-end Sun SMP systems. Thus, several cores can be partitioned for running a single or group of processes and/or threads, while the other cores deal with the rest of the processes on the system.