The issue:
OS: Jetpack 4.4.1
I am running a Nano/D435i depth camera configuration using Donkey Car v 4.1 and also running a Xavier NX/D435i depth camera using the same DC v 4.1.
I realize that the Xavier NX is faster than the Nano, however we have found the following, running the same Donkey Car v 4.1 software on both processors, based on analysis of the data writer part (TubWriter) performance during data recording:
"Ok - I see the problem. On the Xavier run everything looks ok’ish. If you just look at the ‘avg’ column, this gives you the average runtime in ms per part. So the total of that column (assume everything would run sequentially once per loop) should be less than 1000 / car frequency.
On the Nano the TubWriter part takes more, 1000ms for a single call to run, that’s why the car doesn’t react at all.
Even on the Xavier with avg of 12ms it is not as fast as expected (I think it should be < 5ms).
So something is wrong with your write operations on the Nano. Are you writing to an SD card or a disk, there should be tools to check the i/o performance?"
The car drive loop frequency is 20 Hz.
I am using a SanDisk UHS-I 128GB SD card that has a burst write speed approaching 90Mbs/sec and a sustained write speed of around 30MBs/sec on both the Nano and the Xavier NX.
Comments?