Instruction: Extract the value of the target attribute from the given product information and output it along with the corresponding source.

Input:
Product title: Dell XPS X8700-1988blk
Product description: Dell XPS X8700-1988blk
Product feature: Intel Core i7-4790 Processor, 8 GB DDR3, 1TB Hard Drive, Window 7 Home Primium
Product brand: Dell
Target attributes: Processor Speed
Answer: attribute: processor speed
value: None
source: None