TX2 OpenCV StereoBM CPU performance

Autonomous Machines Jetson & Embedded Systems Jetson TX2
#1

We are getting weird results when using the TX2’s CPU. We are running an OpenCV Stereo Block Matching algorithm and it seems like the TX2’s performance is waaay slower than a standard x86 processor. The Jetson is running at 2000ms/frame and on a standard x86 processor it runs at 100ms/frame.

Does anyone happen to know what could be causing this x20 performance hit?

#2

Hi,
Please run in max performance and try again.

$ sudo nvpmodel -m 0
$ sudo jetson_clocks

https://docs.nvidia.com/jetson/l4t/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2Fpower_management_tx2_32.html%23wwpID0E0VN0HA
https://docs.nvidia.com/jetson/l4t/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2Fpower_management_tx2_32.html%23wwpID0E0KB0HA

#3

Thanks for the response.

I’ve tried that already and had the same results.

#4

Hi,
Please run ‘sudo tegrastats’ to check if the system is at max performance.
https://docs.nvidia.com/jetson/l4t/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2FAppendixTegraStats.html

Pure OpenCV application is CPU-based and some hardware blocks(GPU, NVENC, NVDEC) may not be leveraged. Would like to suggest you try gstreamer or tegra_multimedia_api.

#5

Every single core is at 100% and at max speed. The only reason I’m asking the question is we really cannot quantify why the Jetson’s ARM CPU would be 20x worse than a regular x86 performance.

We have suspicions that it might be because of the L2 cache being 2mb.

#6

Hi,
Not sure but OpenCV is mainly developed by Intel. It might run better on x86.

On Jetson platforms, we recommend use tegra_multimedia_api or gstreamer. Hardware acceleration is enabled in the two frameworks.

#7