https://devzone.nordicsemi.com/f/nordic-q-a/113007/filesystem-backend-log-overwrite-takes-a-lot-of-cpuHi all, I am working on an nrf5340 and I activated the FileSystem Backend log to save the logs in my external Flash. It&#39;s working how we are expecting to except once the flash is full. Once the system starts to overwrite data, we see a huge increase ofen-USTelligent Community 13Mon, 15 Jul 2024 13:39:47 GMThttps://devzone.nordicsemi.com/thread/493927?ContentTypeID=1Mon, 15 Jul 2024 13:39:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:2bdda510-a69b-421b-8fa3-e96129b455b5Sigurd Hellesvik<p>Hi,</p> [quote user=""]Once the system starts to overwrite data, we see a huge increase of CPU usage.[/quote] <p>Erasing flash is a time-consuming procedure, and the CPU has to pause during this operations. I am not fully sure how this works with erasing external flash, but it may be similar.<br />Here is the file and place where the driver erases the flash:<br /><a href="https://github.com/nrfconnect/sdk-zephyr/blob/c989b977d31eddf4b90eaf2f146740b6f4c8109a/drivers/flash/nrf_qspi_nor.c#L582">https://github.com/nrfconnect/sdk-zephyr/blob/c989b977d31eddf4b90eaf2f146740b6f4c8109a/drivers/flash/nrf_qspi_nor.c#L582</a></p> <p>Can you add some logging to this function? Then you can see how often and how large areas are erased. That might give us some insight into this.</p> <p>Regards,<br />Sigurd Hellesvik</p><div style="clear:both;"></div>