Designed to lower the energy consumption of server computers, the CPU typically uses 72 W of power at 1.4 GHz.

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 company was purchased by Sun, and the intellectual property became the foundation of the CoolThreads line of processors, starting with the T1.

The UltraSPARC T1 was designed from scratch as a multi-threaded, special-purpose processor, and thus introduced a whole new architecture for obtaining performance.

It was fabricated by Texas Instruments (TI) in their 90 nm complementary metal–oxide–semiconductor (CMOS) process with nine levels of copper interconnect.

The T1 processor can be found in the following products from Sun and Fujitsu Computer Systems: The UltraSPARC T1 microprocessor is unique in its strength and weaknesses, and as such is targeted at specific markets.

However, since the processor's intended markets do not typically make much use of floating-point operations, Sun did not expect this to be a problem.

Sun provides a tool for analysing an application's level of parallelism and use of floating point instructions to determine if it is suitable for use on a T1 or T2 platform.

[7] The T1 only offered a single floating-point unit to be shared by the 8 cores, limiting usage in HPC environments.

This weakness was mitigated with the follow-on UltraSPARC T2 processor, which included 8 floating point units, as well as other additional features.

[10] This allowed the T4 to uniquely mitigate single threaded bottlenecks, while not having to compromise in the overall architecture to achieve massive multi-threaded throughput.

[15] Sun also documented its experience in moving its own online store onto a T2000 server cluster,[16] and have published two articles on web consolidation on CoolThreads using Solaris Containers.

The "Coolthreads(TM)" architecture, beginning with the UltraSPARC T1 (with its positive and negative aspects), was certainly influential in the concurrent and future designs of SPARC processors.

"Rock" was a more ambitious project, intended to support multiple-chip server architectures, targeting traditional data-facing workloads such as databases.

In February 2007, Sun announced at its annual analyst summit that its third-generation simultaneous multithreading design, code-named Victoria Falls, was taped out in October 2006.

[22][23] According to the ISSCC 2010 presentation: "A 16-core SPARC SoC processor enables up to 512 threads in a 4-way glueless system to maximize throughput.

[27] John Fowler, Executive Vice President Systems Oracle, in Openworld 2014 said Linux will be able to run on Sparc at some point.

On March 21, 2006, Sun made the UltraSPARC T1 processor design available under the GNU General Public License via the OpenSPARC project.