If you want to make the most of your Application Class A2 compatible SD card with your Pi 5, you can update to a test kernel via rpi-update that will enable Command Queueing.
Command Queueing allows for asynchronous submission and completion of read/write requests, and the result is a significant performance uplift for multi-threaded and random workloads. On a 64GB Sandisk Extreme U3 A2 card, I get ~2.5x uplift for 4k random read and ~4x for 4k random write as measured by the sdtest.sh script. Mixed read/write workloads will likely see benefits somewhere between the two example figures.
NB: this fundamentally changes the way the block layer interacts with the SD host controller. Don't update a card that has data on that you care about. It is strongly recommended to use alternative media for your root filesystem (USB/NVMe).
To install the test kernel, runIf you encounter a problem, it would help if you included the make and model of the card being used as well as the contents of the card's registers captured with this one-liner:
Command Queueing allows for asynchronous submission and completion of read/write requests, and the result is a significant performance uplift for multi-threaded and random workloads. On a 64GB Sandisk Extreme U3 A2 card, I get ~2.5x uplift for 4k random read and ~4x for 4k random write as measured by the sdtest.sh script. Mixed read/write workloads will likely see benefits somewhere between the two example figures.
NB: this fundamentally changes the way the block layer interacts with the SD host controller. Don't update a card that has data on that you care about. It is strongly recommended to use alternative media for your root filesystem (USB/NVMe).
To install the test kernel, run
Code:
sudo rpi-update SKIP_BOOTLOADER=1 pulls/6046Code:
find /sys/bus/mmc/devices/mmc0\:*/ -type f -not -path "*block*" -not -path "*power*" -print -exec cat {} \;Statistics: Posted by jdb — Fri Mar 15, 2024 3:33 pm