JODY-W377 (Wi-Fi6) communication speed difference caused by i.MX8MQ specification difference

[hbjeong]

Hi NXP team,

I have a question about the communication test using JODY-W377 on i.MX8MQ and i.MX6Q.

The test conditions are

i.MX8MQ - AP mode
(Run iperf -s -u -i1)
i.MX6Q - Station mode
(Run iperf -c 192.168.1.20 -u -b500M -i1 -t 20)

Running the test as shown above will give the following results depending on the part specification of the i.MX8MQ.

Test 1
MIMX8MQ6DVAJZAA
Commercial 0~95 °C
Cortex-A53 CPU speed level : 1.5GHz
Wi-Fi6 Communication speed: Approx. 510Mbps

Test 2
MIMX8MQ6CVAHZAA
Industrial -40~105°C
Cortex-A53 CPU speed level : 1.3GHz
Wi-Fi6 Communication speed : Approx. 250Mbps

(Attach the log files for Test1 and Test2)

The i.MX6Q board is the same for both Test1 and Test2,
i.MX8MQ is the same board, only the AP (i.MX8MQ) is different.

Test1 : Commercial
Test2 : Industrial

If you remove each commercial and industrial AP (i.MX8MQ) and rework them on opposite boards, the symptoms are reversed.
The symptoms are reversed (the speed difference is reproduced depending on the AP).

I should get more than 500Mbps on the i.MX8MQ with industrial -40~105°C spec.
Please let me know if there is any other way to resolve this or if there is a way to test with different settings.

Kind regards.

[shaun_wu]

Hello @hbjeong 

Can you use 'mlanutl mlanX get_sensor_temp' to get chip temperature when throughput is low?

Best Regards

Shaun

[hbjeong]

Regardless of the specific temperature, if all conditions (including temperature) are the same, changing only the AP from MIMX8MQ6DVAJZAA to MIMX8MQ6CVAHZAA reduces the throughput from 500Mbps to 250Mbps.
If all conditions are the same and only the AP is changed, you will see the same behaviour as above.
This has been confirmed by reworking several boards and APs.
I recently received two MIMX8MQ6CVAHZAA from NXP's website and reworked them all, but the symptom is the same.

In conclusion, the commercial version of the AP is capable of 500Mbps performance,
The industrial version of the AP does not have 500Mbps performance.
Can you please explain this?

(Note that, JODY-W377 and i.MX8MQ are operating with PCIE interface.)

Best Regards

[shaun_wu]

Hello @hbjeong 

In conclusion, the commercial version of the AP is capable of 500Mbps performance,
The industrial version of the AP does not have 500Mbps performance.

-->Can you confirm throughput is low when MIMX8MQ6CVAHZAA working in nominal temperature (25℃)? 

Best Regards

Shaun

[shaun_wu]

Hello @hbjeong 

Can you also share test result in sub 0℃ for test case1 and test case2? It is clear that issue is happends on host side. We want to check if it is Layout problem or chipest problem.

Best Regards

Shaun

[shaun_wu]

Hello @hbjeong 

The operation temperature of JODY-W377 (NXP 88w9098 inside) is -40°C to 85°C.

Best Regards

Shaun

[hbjeong]

We need to implement a communication speed of 500 Mbps at sub-zero temperatures.
However, as you can see in the text, 500 Mbps is only working on the Commercial (0-95 °C) version of the AP.

========================================
Test 1
MIMX8MQ6DVAJZAA
Commercial 0~95 °C
Cortex-A53 CPU speed level : 1.5GHz
Wi-Fi6 Communication speed: Approx. 510Mbps

Test 2
MIMX8MQ6CVAHZAA
Industrial -40~105°C
Cortex-A53 CPU speed level : 1.3GHz
Wi-Fi6 Communication speed : Approx. 250Mbps
========================================