Intel® Arc™ A-Series Graphics provides best performance with a resizable BAR but it's not a requirement to run the GPU.
Will Intel® Arc™ A-Series Graphics will still work on a system without a resizable BAR?
Resizable BAR (or Smart Access Memory) must be enabled for optimal performance when using Intel® Arc™ A-Series Graphics. Though, Intel® Arc™ Graphics can still work on a system without Resizable BAR enabled.
Resizable bar is a motherboard feature that can be enabled under BIOS settings. Consult with your motherboard manufacturer to determine whether your motherboard supports resizable BAR.