Hi, we're currently evaluating the software qspi driver performance on the nRF54L15 since it does not come with a dedicated QSPI peripheral like older generations. I wasn't able to find much documentation online or in the SDK on performance. To test I enabled CONFIG_FLASH_SHELL and CONFIG_FLASH_SHELL_TEST_COMMANDS on top of the NCS 3.0.2 spi_flash sample and ran "flash erase_test mx25r6435f@0 0 8192 10". On the nRF52840DK i got the following numbers:
uart:~$ flash erase_write_test mx25r6435f@0 0 8192 10
Loop #1 done in 27ms.
Loop #2 done in 28ms.
Loop #3 done in 28ms.
Loop #4 done in 28ms.
Loop #5 done in 28ms.
Loop #6 done in 28ms.
Loop #7 done in 28ms.
Loop #8 done in 28ms.
Loop #9 done in 28ms.
Loop #10 done in 28ms.
Running this on the nRF54L15DK with the sqspi driver enabled (nrf54l15dk_nrf54l15_cpuapp_sqspi.overlay included) I got significantly worse performance:
uart:~$ flash erase_write_test mx25r6435f@0 0 8192 10
Loop #1 done in 283ms.
Loop #2 done in 241ms.
Loop #3 done in 241ms.
Loop #4 done in 240ms.
Loop #5 done in 241ms.
Loop #6 done in 239ms.
Loop #7 done in 239ms.
Loop #8 done in 239ms.
Loop #9 done in 244ms.
Loop #10 done in 246ms.
This would suggest that sqspi has a 10x worse performance than the dedicated QSPI peripheral on the nRF52840. Is that expected? Are there any supported configurations for increasing the qspi flash access speed?
