6000 Words is not a lot really.

Thers a lot to go at with regards to parallel processing, the history and development would fill 6000 words easily, before going on to specilist applications within the GPU and the rise of the GPGPU with stream processing, development tools such as CUDA and the overall advantages and disadvantages for each.

6000 words would be easily acheivable on the subject for a well researched and referenced project.