Teradata performance statistics
There are a multitude of factors that go into determining which Teradata platform and the configuration of the platform that will suite your needs. Teradata has spent untold amounts of money on intellectual property and decades of experience working with potential customers to help them properly size a configuration that not only meets the immediate needs of a customer but provides them capacity for which the environment can adequately grow and evolve. 

I would strongly suggest you reach out to Teradata directly and engage them in a pre-sales capacity if your company is considering their technology to meet the needs of your data warehouse environment.

For a sandbox environment, you could may be able to get away with using the one terabyte version of Teradata Express on an adequately sized server or consider using Amazon EC2 to stand up a instance of Teradata to complete a proof of concept. It should be noted that either of these options should not be used to gauge the performance of a production environment for service level agreements but whether or not the technology will accomplish what you are trying to do.