Evga says to have the fastest 9800 GTX+. Their card has a shader clock speed of 2 Gigahertz.
9800 GTX by Evga: Now there is an overclocked “+” version.
There are two overclocked versions of the Geforce 9800 GTX+ in Evga's product range: the Superclocked Edition (9800 GTX+ SC) and the SuperSuperclocked Edition (9800 GTX+ SSC).
The clock speeds of the bigger model are set to 792 Megahertz for the GPU, 2 Gigahertz for the shader and 1.15 Gigahertz for the memory. Therewith the Evga 9800 GTX+ SSC is said to be the fastest graphics card of its class - in the opinion of the producer at least. We have not yet been able to produce benchmarks to check this statement.