Windows:
• Windows 7, Windows 8 or later for version 1.x of Elgato Game Capture HD software.
• Windows 7 Service Pack 1 (SP1), Windows 8, or later for version 2.0 (or later) of Elgato Game Capture HD software.
• 2 Ghz (or higher, before any boost or burst mode) dual core CPU, or 2 Ghz (or higher, before Turbo Boost) multi-core i3, i5 or i7 CPU
• Sound card (if your laptop can play sound, then it meets this requirement)
• 4GB Total Installed RAM (or higher)
• Built-in USB 2.0 port
To use Stream Command with the Elgato Game Capture HD 2.0 software:
• 2nd generation Intel Core i7 CPU (i7-2xxx or comparable), 2 Ghz or higher, before Turbo Boost
• Windows 7 Service Pack 1 (SP1), Windows 8, Windows 8.1 or later
This was all copy/paste from their website.