You can play loads of dings on an integrated GPU card. We were talking about a core 2 duo replacement on/for a GL960 Express Board so with a choice limitation on the CPU replacement, I am not sure that you would get any improvements
Well larger cache = more fast storing access read, if you don't do much of multi-tasking, you won't take advantage of that larger cache size. Relying on the larger cache alone won't speed up performance that much
Minimum System Requirements for Roxio Game Capture: Windows 7/Vista/XP Intel Core 2 Duo Processor 1.8 GHz or AMD Athlon x2 64 2.0 GHz 2GB RAM. DirectX 9.0c compatible graphics card or higher sound card. 2GB free hard drive space for installation. 10+ GB free recommended for video recording. Windows Media Player 11 or higher. Inter explorer 7 or 8.
It does not say at what point of system requirements for the Capturing to be smooth. So, I don't know the answer to the "lot less lag"