Hello. I used a FPGA to send data to pc with FT232H in synchrouous 245 mode. The FPGA sends 32 bytes every 1uS (then the rate is 32MB/s). The PC softeware uses the FT_Read function and The basic receiving is OK. But the date rate with Bushound to moniter is only 24.5MB/S and the nTXE signal is frequently High. It seems the FT_Read function runs slowly reading the Buffer and a thread is set for it without any othor operations in it. The most rate would be 40MB/s according to the FT232H datasheet.  So why? Thank you!