realsense-ros: Incredibly slow with librealsense 2.45, realsense_ros 2.3.0

Hi,

As this is my first realsense installation, I have no frame of reference, but launching rs_rgbd.launch or rs_camera.launch cause ~140% CPU usage by nodelet, and present frames at ~2fps in RViz. The entire computer (8-core 2.9GHz, 16GB ram) becomes almost unusable.

I’m on librealsense 2.45, realsense_ros 2.3.0, using a D435i. I installed with:

apt-get install -y librealsense2-dkms
apt-get install -y librealsense2-utils
apt-get install -y librealsense2-dev
apt-get install -y librealsense2-dbg
apt-get install -y ros-melodic-realsense2-camera
apt install -y ros-melodic-rgbd-launch

This seems to be a problem reported by others e.g. at #1887

I have tried switching off as much processing in the launchfiles as I can, but this doesn’t seem to change anything

realsense-viewer uses ~95% CPU with just the stereo module on, and frame drops are around 65% there.