Yes, I am seeing a little differences with the speed, but not much. It would still be good to know how this is handled at the device driver level. For example suppose I give it a 256 byte buffer to output, does it use DMA to output it? Does it spin on waiting for each SPI output (I assume not), or is it fielding an interrupt after each output. Is there any hardware FIFO queue or is it each transfer at a time?
Kurt