Use with X3-series Adapters

Applications are unaffected, Onload deals with underlying architectural differences, and the data visible to the application via the sockets API is unaffected.

The following architectural differences affect receive:

• Maximum of 256 filters.
• Filtering is by 3-tuple (remote IP address and port).
• No receive-side scaling.

The following architectural differences affect transmit:

• Maximum of 15 applications for unshared TX queues (16 queues).
• All transmission is by reliable CTPIO with stable performance.
• No hardware checksums.
• Frequent polling is essential to achieve reasonable packet rate due to small transmit buffer in hardware.

The following difference affect tuning:

• On X3522 the xilinx_efct net driver must perform regular work to keep the RX path supplied with buffers, including when using Onload/TCPDirect/ef_vi.
• Ensure that xilinx_efct interrupts are delivered to CPU cores that have sufficient capacity and can be handled in a timely fashion to avoid underruns.

For more detailed information about X3-series adapters and their differences from predecessors, see the Alveo X3522 User Guide (UG1523).