"Externally, it would be unlikely for one to immediately notice a difference between the MacBook Pro Core 2 Duo Santa Rosa models -- the MacBook Pro "Core 2 Duo" 2.2 15" (Santa Rosa), "Core 2 Duo" 2.4 15" (Santa Rosa), and "Core 2 Duo" 2.4 17" (Santa Rosa) -- and their predecessors as each share identical cases. The 15-Inch "Santa Rosa" models weigh slightly less (5.4 pounds compared to 5.6 pounds) than the replaced systems, but one would have to be incredibly perceptive to notice such a minute difference.
With a 15-Inch "Santa Rosa" model and a 15-Inch model from the previous series side-by-side, however, one likely would notice that the "Santa Rosa" systems have a brighter "mercury-free power-efficient LED-backlit" 15.4" widescreen 1440x900 TFT active-matrix display. The 17-Inch "Santa Rosa" model has the same 17" widescreen CCFL-backlit 1680x1050 TFT active-matrix display as its predecessor, although a higher-resolution 1920x1200 display also is available by custom configuration.
All connectivity effectively is the same, with an ExpressCard/34 slot, AirPort Extreme (although the "Santa Rosa" models have 802.11n enabled by default), Bluetooth 2.0+EDR, Gigabit Ethernet, FireWire "400" port, Firewire "800" port, two USB 2.0 ports (three on the 17-Inch system), optical digital audio in/out, and DVI out. The "Santa Rosa" models also share the same fiber-optic-based "ambient light sensor" that adjusts keyboard illumination and screen brightness, "scrolling TrackPad", "MagSafe" power connector, integrated iSight video camera, and included Apple Remote.
Internally, the differences are more substantial. The "Santa Rosa" models use a more advanced architecture with a faster frontside bus (800 MHz compared to 667 MHz), additional RAM capacity (4 GB instead of 3 GB), a faster graphics processor (NVIDIA GeForce 8600M GT instead of the ATI Mobility Radeon X1600), and superior power management (including a dynamically adjustable frontside bus, which when combined with the backlit LED display on 15-inch models results in an extra hour of estimated battery life and an additional 15 minutes on the 17-inch system). The 15-Inch "Santa Rosa" systems also have a slightly faster dual-layer SuperDrive (8X compared to 6X)."
Extract from:
http://www.everymac.com/systems/app...ro-santa-rosa-and-macbook-pro-core-2-duo.html