[Supported feature] Memory-constrained devices [Description] 
You can use the emulator to test your app on images that emulate the following memory-constrained devices: Emulator WVGA 512MB, for apps that target Windows Phone 8. Emulator WVGA 512MB, Emulator 7.8 256MB, and Emulator 7.1 256MB, for apps that target Windows Phone OS 7.1. For more info, see Developing apps for lower-memory phones for Windows Phone 8.