CPU and Memory
"Civilization V" requires a dual-core processor to run and 2 gigabytes (GB) of random access memory (RAM) on Mac and Windows-based PCs. Very few computers are made with single core processors and those computers are usually netbooks. 2 GB of DDR2 RAM is less than the typical RAM of a new system, which is more likely to be 4 GB of DDR3 RAM.
Operating System
For the PC, "Civilization V" supports Windows XP SP3 (the latest version,) Windows Vista SP2 and Windows 7. On the Mac, only the current OS, Mac OS X Snow Leopard (10.6.4.,) supports "Civilization V."
Video
ATI and nVidia GPUs are common to Windows PCs and Macs. These should have at least 256 megabytes (MB) of VRAM and be equivalent to or greater than the ATI HD2600 XT or the nVidia 7900 GS. Both series of cards are essentially equivalent to integrated graphics, especially on laptops.
Miscellaneous
Because "Civilization V" can be purchased digitally through Steam or other online retailers, it isn't necessary to have a DVD-ROM player. There must be 8 GB of storage free to install the game and at least DirectX 9.0c must be installed to run this game.