SPI data rate ad-hoc mode

My network is XB24 wi-fi module (IBSS creator mode) <----> PC. I use SPI interface for communication (SPI master is ADSP BF-533). Data is transmitting in API mode (“AT AP 1”). After transmitting each API packet transmit request API packet is receiving (page 49 “90002124_E.pdf”). If status is “sucsess” the next packet is sending. Max spi data rate is about 680 Kbps. When speed up SPI data rate transmit request isn’t receiving. I used UDP and TCP IP protocols, different channels and so on but data rate was the same. Did you have the same problem? What is your max SPI data rate? XB24-WF firmware version is 102B. Thanks In Advance!