The Raspberry Pi Compute Module 3 is a pin compatible successor to the Compute Module 1 (there is no CM2) that, according to the Raspberry Pi Foundation, offers twice the RAM and 10-times the CPU performance.
Note that while the Compute Module 3 may be able to be a drop in upgrade / replacement for devices powered by the first generation CM1, it uses more power, puts out more heat, and is 1mm taller so while it is pin compatible it may not work in all devices if their module slot space, power supply, and airflow / heatsinks are not up to the task.
The Compute Module 3 is a small single board computer with a SO-DIMM connector that can slot into embedded and IoT products. It is powered by a Broadcom BCM2837 with four ARM Cortex-A53 CPU cores clocked at 1.2 GHz and a dual core VIdeoCore IV GPU clocked at 400 MHz. The processor is paired with 1GB of RAM. As far as onboard storage, the Compute Module 3 will come in two SKUs: the CM3 with 4GB of eMMC or a CM3 Lite without pre-installed eMMC and solder points for manufacturers to add their own eMMC or micro SD card slot. The VideoCore IV GPU supports 1080p30 decode of H.264. Users wanting hardware decode of H.265 and/or 4K support will have to look elsewhere. As is usual with Broadcom, exact specifications of the BCM2837 (especially their GPU) are kept close and quiet, unfortunately.
The exact ports and I/O from the Compute Module 3 will depend on the device and what manufacturers implement and wire to the connectors on the SO-DIMM slot. However, looking at the CMIO3 development board (96 Euros, $116 USD) shows that the CM3 supports GPIO, USB, micro USB, CSI (camera interface), DSI (display interface), HDMI, micro SD, audio, and networking.
The Compute Module 3 can run Windows IOT Core or any number of Linux distributions compatible with ARM processors.
The Compute Module 3 is $30 while the “lite” variant without eMMC is $25. A kit including the development I/O board and both CM3 SKUs is $200. NEC has already announced it will be using the new Compute Module 3 in their digital signage and displays. Other applications include Smart TVs, home automation, and industrial control systems as well as hobbyist projects and robotics.