OS: Android 4.1.1
The Samsung Galaxy S II incorporates the powerful Samsung 1.2-GHz Exynos dual-core system-on-chip. The Exynos integrates RISC-based CortexA9 application-processor cores with its Mali 400MP ARM-based GPU, and communicates with the system's 1 GB of memory at 6.4 GB/s. That's adequate bandwidth to keep its 800-by-480 Super AMOLED Plus 3-D video display, 1080p video capture and HDMI output all working smoothly.
Galaxy S II includes an 8MP back camera, 2MP front camera, Wi-Fi Direct plus a/b/g/n, Bluetooth 3.0, GPS, DivX playback, stereo FM radio, and dual MicroUSB and HDMI outputs. As if that weren't enough, Samsung adds to the Galaxy S II a UI layer called TouchWiz that runs atop Android (as well as Samsung's Bada OS for its low-end phones).