user: Question: What is the speed of the model whose number is W3540?
Columns: ['model', 'Speed (GHz)', 'L3 Cache (MB)', 'QPI speed (GT/s)', 'DDR3 Clock (MHz)', 'TDP (W)', 'Cores', 'Threads', 'Turbo-Boost']
Types: ['text', 'text', 'real', 'text', 'real', 'real', 'real', 'real', 'text']
Sample row: ['W3503', '2.40', 4.0, '4.8', 1066.0, 130.0, 2.0, 2.0, 'No']
SQL:

assistant: SELECT "Speed (GHz)" FROM "Table" WHERE "model" = 'W3540';