The Cray XMT (codenamed Eldorado) is the third generation of the Cray MTAsupercomputer architecture originally developed by Tera. The earlier generations were called the Cray MTA and the Cray MTA-2. The XMT makes the MTA's multithreaded processors, now dubbed Threadstorm, compatible with the 1207-pin Socket F used by AMDOpteron processors. The Threadstorm processors are plugged into systems otherwise identical to the Cray XT4.
The Threadstorm processors only execute user code, on top of a simple BSD Unix-based microkernel called MTX; system I/O is performed by Opteron processors running Linux. This third generation MTA system improves clock speed from 220 MHz to 500 MHz, the maximal processor count from 256 to 8192, and maximum memory to 128 TB.
The architecture has been reworked in CPUs such as Threadstorm4 which is used by the XMTs technological successor: YarcData's Urika line of big data appliances.