The Mac mini "Core 2 Duo" 2.66 (Late 2009) is technically a "build-to-order" configuration of the Mac mini "Core 2 Duo" 2.53 (Late 2009), but it is also documented separately for user convenience. Aside from processor speed, the two models are the same.
The Apple Mac mini "Core 2 Duo" 2.66 (Late 2009) is powered by a 2.66 GHz Intel "Core 2 Duo" (P8800) processor with a 3 MB on-chip L2 cache and a 1066 MHz frontside bus. It includes 4 GB of 1066 MHz DDR3 SDRAM (PC3-8500), a 320 GB Serial ATA hard drive, a slot-loading 8X double-layer "SuperDrive", and a NVIDIA GeForce 9400M graphics processor with 256 MB of shared system memory.
For connectivity, it offers Mini-DVI and Mini DisplayPort, a Firewire "800" port, five USB 2.0 ports, combined "optical digital audio input/audio line in" and "optical digital audio output/headphone" minijacks, a 10/100/1000Base-T Gigabit Ethernet port, and built-in AirPort Extreme (802.11a/b/g/n) and Bluetooth 2.1+EDR.
Late 2009 Mac mini models enclose their internal components in a tiny, elegant 2.9 lb, 6.5-inch square, two-inch-tall case that contains a built-in speaker and an external power supply. All Mac mini systems are shipped without a display, keyboard, or mouse, but numerous Apple and third-party options are available.