Fast data transmission over PCIe with Xillybus

Autonomous Machines Jetson & Embedded Systems Jetson TX2
#1

Hi Guys,

we need a fast data transmission between a Xilinx Artix 7 (AC701 Eval Board) and Nividia Jetson TX2 Board.
We want to send 48 MByte data every 50 milliseconds from Artix 7 to Jetson TX2.
We try it with a IP-Core from Xillybus (http://xillybus.com).
The support from Xillybus told me the following:

“There is however a cache coherency issue with ARM-based platforms, which slows down I/O considerably, so I’m not all that sure about the NVidia platform.”

So my questions is:
Does anybody have experience with PCIe and Xillybus on TX2 or do you think this is possible with the TX2 Board?

Thx for your help!
regards
Sebastian

#2

48 MByte / 50 milliseconds is effectively 7.68 Gbps and TX2 supports 10Gigabit ethernet bandwidth over PCIe -x4 (Gen-2). So, TX2 satisfies yous requirement.

#3

Do you know something about this “issue”?

“There is however a cache coherency issue with ARM-based platforms, which slows down I/O considerably, so I’m not all that sure about the NVidia platform.”

#4

TX2 doesn’t have IO-Coherency enabled, so, it means that, APIs like dma_alloc_coherent() etc… return uncached memory, so, if the same memory is being used by both CPU and PCIe, there is a penalty because of the memory being uncached. But, that penalty won’t affect this particular use case.