Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_73709 ( "Model" text, "Launch" text, "Model Number" text, "Code name" text, "Fab ( nm )" text, "Bus interface" text, "Memory ( MiB )" text, "Core clock ( MHz )" text, "Memory clock ( MHz )" text, "Config core 1" text, "Pixel ( GP /s)" text, "Texture ( GT /s)" text, "Bandwidth ( GB /s)" text, "Bus type" text, "Bus width ( bit )" text, "DirectX" text, "OpenGL" text, "Processing Power GFLOPs" text, "TDP (Watts)GPU only" text, "Features" text )

### Question ###
How many values for bus width have a bandwidth of 25.6 and model number of Granville Pro?

### Accurate SQL ###

SELECT COUNT("Bus width ( bit )") FROM table_73709 WHERE "Bandwidth ( GB /s)" = '25.6' AND "Model Number" = 'Granville Pro'