For questions truly specific to the "Sony Ericsson Xperia Arc" (Xperia X12) device.
The Sony Ericsson Xperia Arc was launched in Europa in April 2011, running Gingerbread, and was updated to Android 4.0 (ICS) in about June 2012.
Sony Ericsson Xperia Arc (source: GSMArena)
- CPU: Qualcomm MSM 8255 1 GHz Scorpion
- GPU: Adreno 205
- RAM: 512 MB
- internal storage: 320 MB
- removable: microSD up to 32 GB
- display: 4.2" 854×480 px FWVGA TFT LCD
- rear camera: 8 MPx
Full device specifications can be found at GSMArena.