Instruction: First, identify the target attributes from the provided list. Then, scan the product title, description, feature, and brand to extract the values associated with each target attribute. Finally, create a list of dictionaries, each containing the extracted attribute, its corresponding value, and the source where it was found.

Input:
Product title: Acer Predator AG5900-U3092 Mainstream Gaming Desktop (Black) (Discontinued by Manufacturer)
Product description: Acer Predator AG5900-U3092 Mainstream Gaming Desktop comes with these specs: Intel Core i7-870 Processor 2.93GHz with Turbo Boost Technology up to 3.6GHz, Windows 7 Home Premium, Intel H57 Express Chipset, 8GB DDR3 Memory, ATI Radeon HD 5850 Graphics Card with 1GB of Discrete Video Memory, 1.5TB 7200RPM SATA Hard Drive, Multi-in-1 Digital Media Card Reader, High-Definition Audio Support with 5.1-channel Audio Support, 12 - USB 2.0, HDMI, Gigabit Ethernet ports, USB Keyboard and Mouse, 33.0 lbs. | 15 kg (system unit only), 1 Year Parts and Labor Limited Warranty with Toll-Free Tech Support, Registration/ Limited Warranty Card, McAfee Internet Security Suite Trial, Microsoft Office Starter 2010, Complete your PC. Buy full-featured Microsoft Office 2010.
Product feature: The newly designed Predator Desktop combines a richer HD gaming experience with efficient productivity, providing the flexibility to enjoy exciting games and home computing tasks at the same time., Extend your PC performance with the Intel Core i7 processor with Intel Turbo Boost Technology. Attain advanced performance for gaming, multitasking, rich content creation and increased productivity for incredible system response., 8GB DDR3 Memory delivers insane system speed to handle serious graphics demands in game-critical situations and lets you experience ultra-fast frame rates during game play., ATI Radeon HD 5850 Graphics with 1GB of dedicated video memory lets you experience the newest DirectX 11 games at mind blowing frame rates with lightning fast video and jaw dropping effects in extreme HD resolutions., Save games, movies, music and more on the whopping 1.5TB hot-swap Hard Drive, and then take it with you! 2 additional easy-swap hard drive cages let you swap or add drives easily and expand storage capacity!
Product brand: Acer
Target attributes: Graphics Processor
Answer: attribute: graphics processor
value: radeon
source: product description
attribute: graphics processor
value: radeon
source: product feature