Reduce the latency of DMA

[dajovu1022]

Hi,
We would like to reduce the latency of XDMA.
Are there any suggestions?

1) Do you suggest to use XDMA or QDMA or any other DMA engines for less latency?
2) Any software/FPGA configuration you suggest to reduce the latency?

<PS>
The development platform we use is Alveo U280.
The current version Vivado we use is 2020.1 and XDMA is used now.

[mcertosi]

Hi @dajovu1022 

See if the discussion here is relevant to you - https://forums.xilinx.com/t5/Alveo-Accelerator-Cards/U50-XDMA-direct-access/td-p/1156053 

We recommend qdma for lower latency, we recommend the ethernet ports for consistent latency as there is high overhead for PCIe. It doesn't look like there is a QDMA shell coming for the U280, you should contact your xilinx marketing or sales rep to see if there are any Ethernet enabled shells. 

We recommend transferring data directly to PL ram (instead of offchip on the accelerator card) for reducing latency even further. 

Regards,

M

[dajovu1022]

Hi,

Thank you for your feedback.
The main environment we used is Vivado flow.
Are there any reference design for low latency DMA with Vivado flow?

Thanks.