The MacBook Pro "Core 2 Duo" 2.53 15" (SD - Mid-2009) features a 45 nm "Penryn" 2.53 GHz Intel "Core 2 Duo" processor (P8700), with two independent processor "cores" on a single silicon chip, a 3 MB shared "on chip" level 2 cache, a 1066 MHz frontside bus, 4 GB of 1066 MHz DDR3 SDRAM (PC3-8500) installed in pairs (two 2 GB modules), a 250 GB Serial ATA (5400 RPM) hard drive, an 8X DL "SuperDrive", a NVIDIA GeForce 9400M "graphics processor with 256 MB of DDR3 SDRAM shared with main memory", integrated iSight, and an LED-backlit 15.4" widescreen TFT active-matrix "glossy" display (1440x900 native resolution).
Connectivity includes AirPort Extreme (802.11a/b/g/n), Bluetooth 2.1+EDR, Gigabit Ethernet, a Firewire "800" port, two USB 2.0 ports, optical digital/analog audio in/out, a "Mini DisplayPort" that supports an external display at 2560x1600, and an SD card slot. It lacks an ExpressCard/34 slot.
This model uses essentially the same "Unibody" case design -- one milled from a single block of aluminum -- as the previous 15-Inch MacBook Pro models that the "Mid-2009" line replaced, and it has the same backlit keyboard and "no button" glass "multi-touch" trackpad with support for "four finger" gestures and programmable "zones", and a very similar internal architecture, but there are notable differences as well. The "Mid-2009" 15-Inch MacBook Pro models have an improved display (said to have "60% greater color gamut"), and have a non-swappable battery design that provides 7 hours of battery life (up from 5 hours). They also add the aforementioned SD card slot, but drop the previously standard ExpressCard/34 slot. Also be sure to note that this entry-level model has integrated graphics.