According to https://docs.microsoft.com/en-us/windows-hardware/design/minimum/minimum-hardware-requirements-overview https://docs.microsoft.com/en-us/windows-ha

According to https://docs.microsoft.com/en-us/windows-hardware/design/minimum/minimum-hardware-requirements-overview https://docs.microsoft.com/en-us/windows-hardware/design/min..., IoT Core needs 256MB of RAM. The Azure Sphere will run on 4. So that seems to validate that it can't actually scale down quite as far.