Microsoft Lumia 640 Microsoft is another pocket size windows phone Lumia 640 come with Micro-SIM option and runs Microsoft Windows Phone 8.1 with Lumia Denim operating system. It has 5 inches display having 720 x 1280 pixels resolution and the display is protected with Corning Gorilla Glass 3 and clear black display. The windows phone has Quad-core 1.2 GHz Cortex-A7 processor, Qualcomm MSM8926 Snapdragon 400 chipset with Adreno 305 GPU paired with 1GB of RAM and 8GB internal memory option which can be further extended up to 128 GB via microSD card. The Microsoft Lumia 640 has 8 MP, 3264 x 2448 pixels, autofocus, LED flash and has 1 MP, 720p frontfacing camera. The handset is energized by Li-Ion 2500 mAh battery support 2G and 3G connectivity.