A basic WICED app with Wi-Fi and BT will require about 300k bytes of internal flash. The Wi-Fi firmware is about 400k bytes and can live in either internal or SPI flash memory. The internal flash is 1 Mbyte.
If you’re using SPI flash for the Wi-Fi firmware, there is roughly 700k bytes free in the internal flash. If you’re using internal flash for the Wi-Fi firmware, you have roughly 300k bytes available.
There is a penalty at power-up for putting W-iFi firmware in SPI flash. Loading the firmware from SPI flash takes several (approx. 5) seconds. Loading the firmware from internal flash is considerably faster. After power-up, there is no difference.