Minimum:

OS: Win 7
Processor: 1.8 GHz Intel Core 2 Duo (equivalent AMD CPU)
Memory: 2 GB RAM
Graphics: Supported chipsets: NVIDIA 7900 or better; ATI X1800 or better. Please note that NVIDIA GeForce 9300, 8500, 8400, and 8300 are below minimum system requirements, as are AMD/ATI Radeon HD3200, HD3300, and HD4350. Updates to your video and sound card drivers may be required.
DirectX: Version 9.0c
Storage: 15 GB available space
Sound Card: DirectX 9.0c compatible
Additional Notes: Supported chipsets: NVIDIA 7900 or better; ATI X1800 or better. Please note that NVIDIA GeForce 9300, 8500, 8400, and 8300 are below minimum system requirements, as are AMD/ATI Radeon HD3200, HD3300, and HD4350. Updates to your video and sound card drivers may be required.

Mass Effect 3 N7 Digital Deluxe Edition screenshots