Performance
Powering the Lumia 638 is a Qualcomm Snapdragon 400 chipset with a quad-core 1.2 GHz Cortex-A7 CPU and an Adreno 305 GPU. Coupled with 1GB of RAM, the phone offered smooth performance for everyday tasks such as browsing, social media, and light gaming on the Windows Phone 8.1 operating system. It handled multitasking with moderate efficiency, but intensive applications or games could push the device to its limits. The internal storage of 8GB, though modest, was expandable via a microSDXC card slot, providing users with additional space for their apps and media.