The Ubisoft forums offer the system requirements for IL-2 Sturmovik: Cliffs of Dover, 1C's upcoming combat flight simulator. These specs follow.

OPERATING SYSTEM: Windows® 7 / Vista SP2 / Windows XP SP3
PROCESSOR: Pentium® Dual-Core 2.0GHz or Athlon™ X2 3800+ (Intel Core i5 2.66GHz or AMD Phenom II X4 2.6GHz recommended)
RAM: 2GB (4GB recommended)
VIDEO CARD: DirectX® 9.0c compliant, 512Mb Video Card (1GB DirectX® 10 recommended) - See supported List*
DIRECT X®: DirectX® 9.0c or DirectX® 10 (included on disc)
DVD-ROM DRIVE: 8X
SOUND CARD: DirectX 9.0c compatible
HARD DISK: 10GB
PERIPHERALS: Mouse, keyboard (joystick with throttle and rudder control recommended)
MULTIPLAY: Broadband connection with 128 kbps upstream or faster

*SUPPORTED VIDEO CARDS AT TIME OF RELEASE:
ATI® 4850/4870/5830/5850/5770/5870/6870/6950/6970
NVidia®: 8800/9800/250/260/275/285/460/465/470/480