Compare mini and air
mini :
2.4GHz or 2.66GHz Intel Core 2 Duo processor
3MB on-chip shared L2 cache
1066MHz frontside bus
2GB (two 1GB SO-DIMMs) of 1066MHz DDR3 SDRAM; two SO-DIMM slots support up to 8GB
NVIDIA GeForce 320M graphics processor with 256MB of DDR3 SDRAM shared with main memory4
Mini DisplayPort with support for up to 2560-by-1600 resolution
HDMI port with support for up to 1920-by-1200 resolution
DVI output using HDMI to DVI Adapter (included)
VGA output using Mini DisplayPort to VGA Adapter (sold separately)
Support for extended desktop and video mirroring across both ports
air:
1.86GHz Intel Core 2 Duo processor with 6MB on-chip shared L2 cache; or optional 2.13GHz Intel Core 2 Duo processor with 6MB shared L2 cache
1066MHz frontside bus
2GB of 1066MHz DDR3 SDRAM onboard (4GB maximum)
NVIDIA GeForce 320M graphics processor with 256MB of DDR3 SDRAM shared with main memory3
Dual display and video mirroring: Simultaneously supports full native resolution on the built-in display and up to 2560 by 1600 pixels on an external display, both at millions of colors