Today EVGA has released four different versions of the GTS250. The four models include 512mb as well as a 1gb model. There are two cards for the 512 and 1gb models which include a superclocked version of each. The superclocked versions have the following specs:
Core Clock: 771MHz
Processing Cores: 128
Memory Clock Speed: 2246MHz
Memory Bandwidth: 71.8GB/sec
Shader Clock Speed: 1890MHz
Bus: PCI-E 2.0
Shader Clock Speed: 1890MHz
Bus: PCI-E 2.0
The normal card, not overclocked, has slightly lower clock speeds.