Some USB sticks expose a bad performance. The current DMA mode can be verified by checking the system logger output (sloginfo) after starting the the devb-umass driver. Sometimes it's required to enable DMA via the the "cam bounce" driver argument.
NOTE:
This entry has been validated against the SDP version listed above. Use
caution when considering this advice for any other SDP version. For
supported releases, please reach out to QNX Technical Support if you have any questions/concerns.