The MacBook Pro "Core i7" 3.1 13-Inch (Early 2015 Retina Display) originally was a "configure-to-order" configuration for both the MacBook Pro "Core i5" 2.7 13-Inch (Early 2015 Retina Display) and MacBook Pro "Core i5" 2.9 13-Inch (Early 2015 Retina Display), but also is documented as a separate model for reader convenience. Starting on October 27, 2016, it only is a CTO option for the MacBook Pro "Core i5" 2.7 13-Inch (Early 2015 Retina Display). The processor (and the corresponding larger level 3 cache), are the only substantial differences between this model and its stock compatriots.

The MacBook Pro "Core i7" 3.1 13-Inch (Early 2015 Retina Display) features
a 14 nm "Broadwell" 3.1 GHz Intel "Core i7" processor (5557U),
with dual independent processor "cores" on a single silicon chip,
a 4 MB shared level 3 cache,
8 GB of onboard 1866 MHz LPDDR3 SDRAM,
512 GB of 4 Lane PCIe-based flash storage, and
an integrated Intel Iris Graphics 6100 graphics processor that shares memory with the system.

It also has
an integrated 720p FaceTime HD webcam, and
a high-resolution LED-backlit 13.3" widescreen 2560x1600 (227 ppi) "Retina" display
in a case that weighs just less than 3.5 pounds (1.58 kg).

It does not have an internal optical drive.

Connectivity includes
802.11ac Wi-Fi,
Bluetooth 4.0,
two USB 3.0 ports,
two "Thunderbolt 2" ports,
an HDMI port,
an audio in/out port, and
an SDXC card slot.

In addition, this model has
a backlit keyboard,
a clever haptic-capable "Force Touch" trackpad and
an internal, sealed battery.

Compared to its predecessor, this model looks nearly identical externally, but it has a more advanced processor and architecture, more advanced graphics processor, faster RAM, a faster SSD, and a higher capacity battery as well as the aforementioned more advanced "Force Touch" trackpad.

Please note that stock images are used.