AM6548: RTOS PRU-ICSSG bandwidth

Alexander Aganichev

Part Number: AM6548

Hello!

Is there table with expected bandwidth of the PRU-ICSSG on the various types of packets with TI-RTOS?

According to http://software-dl.ti.com/processor-sdk-linux/esd/docs/latest/linux/Industrial_Protocols_HSR_PRP.html#performance-test-and-logs the throughput is dramatically drops on AM437x and AM57xx with decreasing packet size. We need to receive huge number of short (128 bytes long or so) packets and desiding if AM6x will work for our use.

over 6 years ago

0 Garrett Ding over 6 years ago

TI__Mastermind 43296 points

Alex,

I will try to find out the PRU-ICSSG bandwidth benchmarks on AM65x IDK. Considering the theoretical bandwidth limit of Gigabit interface from PRU-ICSSG versus 100Mbps interface from PRU-ICSS on AM437x/57xx, the actual bandwidth with short packets should increase dramatically.

Regards,
Garrett

0 Nick Saulnier over 6 years ago in reply to Garrett Ding

TI__Guru** 100740 points

Hello,

Could you clarify if you were talking about Standard PRU Ethernet, HSR/PRP, or something else?

Regards,

Nick

0 Alexander Aganichev over 6 years ago in reply to Nick Saulnier

Intellectual 620 points

Hello, Nick!

It would be nice to see both standard PRU Ethernet and HSR charts, but as far as I know PRP/HSR is not released yet.

Regards,
Alexander

0 Nick Saulnier over 6 years ago in reply to Alexander Aganichev

TI__Guru** 100740 points

Hello Alexander,

I can only comment from the Linux side, Garrett may have different information from the RTOS side.

We have not released official bandwidth benchmarks for Linux AM65x PRU Ethernet at this point in time. I think the plan is to start providing those in the next SDK release.

NOTE! THESE ARE NOT OFFICIAL RESULTS OR A GUARANTEE OF PERFORMANCE. THESE ARE JUST GENERAL NUMBERS THAT I CAN OBSERVE ON AM65x EVM RUNNING LINUX SDK 6.0. Here are some iperf tests between a Linux PC and the AM65x EVM running Linux with the default packet size:

TCP TX: 840Mbits/sec
TCP RX: 800Mbits/sec
TCP RX&TX simultaneous: 495Mbits/sec

UDP TX: 700Mbits/sec
UDP RX: 770Mbits/sec

I did not test with different packet sizes, but hopefully this gives a rough idea of performance.

Regards,

Nick

0 Alexander Aganichev over 6 years ago in reply to Nick Saulnier

Intellectual 620 points

Hello Nick,

Thank you! But my concern is performance on small packets. Our tests on AM437x shows the bandwidth drops significantly down to just 44Mbits/sec with drops or just 9Mbits/sec without drops on SGMII port (by the way, is there official chart?), so it whould be nice to see these numbers for the 128 bytes long packets to compare.

Reagrds,
Alexander

0 Nick Saulnier over 6 years ago in reply to Alexander Aganichev

TI__Guru** 100740 points

Hello Alexander,

From the Linux side, we currently only publish the CPSW Ethernet throughput numbers in the Kernel Performance Guide for each SDK release. I am talking with the team about adding PRU Ethernet throughput numbers in future SDK releases.

I suggest that you run tests on an AM65x EVM or IDK to see if the throughput is appropriate for your use case.

Please use Processor SDK 6.0 or later in your tests (for both RTOS and Linux). SDK 6.0 adds several important bug fixes to the AM65x PRU-ICSSG Ethernet firmware. Note that AM65x PRU Ethernet is still considered beta software, so there will be additional bug fixes in the future. However, I think SDK 6.0 should give a general idea of performance.

Regards,

Nick

0 Garrett Ding over 6 years ago in reply to Alexander Aganichev

TI__Mastermind 43296 points

Alex,

>>We need to receive huge number of short (128 bytes long or so) packets

How much Kpps in the use case?

We have some test results with standard PRU Ethernet but it's not ready for official publication yet.

Regards,

Garrett

0 Alexander Aganichev over 6 years ago in reply to Garrett Ding

Intellectual 620 points

Garrett,

We need no less than 110Kpps without drops.

Regards,
Alexander

0 Garrett Ding over 6 years ago in reply to Alexander Aganichev

TI__Mastermind 43296 points

Alexander,

The ICSSG driver developer who collected the throughput result is on vacation till Sep.3. I will confirm with him for the 110Kpps 128 bytes throughput after he is back to the office.

Regards,
Garrett

0 Garrett Ding over 6 years ago in reply to Garrett Ding

TI__Mastermind 43296 points

Alexander,

Our test results show >3x higher than you required 110Kpps for 128 bytes payload with Processor SDK v5.3, and we don't expect any performance degradation on the latest PRSDK v6.0.

Regards,

Garrett

0 Alexander Aganichev over 6 years ago in reply to Garrett Ding

Intellectual 620 points

Garrett,

Thank you.

That means that numbers from Linux Kernel Performance Guide (listed above) will likely be updated as well (now it's 36kpps egress/89 kpps ingress which are 10/3-4 times lesser than with RTOS).

Regards,

Alexander

Processors

Processors forum

AM6548: RTOS PRU-ICSSG bandwidth