Network performance difference between Kernel 4.4 (Jetpack 3.2.1) and Kernel 4.9 (Jetpack 4.2.1)

I have a big problem with the new Jetpack 4.2.1 including the kernel 4.9 on a Jetson TX2.

I´m running a Xilinx FPGA over PCIe with a Xilinx PCIe Driver ( With Jetpack 3.2.1 (Kernel 4.4) everything is good!

But with the new Jetpack 4.2.1 (Kernel 4.9) i have a big network performance issue while running my application using the PCIe Driver. With iperf i get a result of 50-100 MBit. When i stop my application the iperf result is about 950 MBit.

With the JetPack 3.2.1 (Kernel 4.4) i have no network performance problems. Everytime my iperf result is about 950 MBit.

I tried to compare the 4.4 and 4.9 kernel config. But there are so many changes that i don´t know what´s the problem.

Is there somebody who can help me or give me a hint?


Hi Sebastian,

Could you also try the test on rel-28.3? I would like to narrow down what may cause such problem.


Also, I believe you already used jetson clocks during the test, right?

Hi sebastian_w,

Have you managed to get issue resolved? Any result can be shared?