PLDA and Samtec, today announced a demo of their combined PCIe 4.0 solution that delivers full PCIe 4.0 bandwidth (16 GT/s) over copper or optical fiber at minimal cost. 

The solution is based on a PLDA PCIe 4.0 acquisition board running PLDA’s PCIe 4.0 controller IP combined with Samtec’s FireFly™ Micro Flyover System™. This demo suggests a solution to overcoming the inherent limitations of maintaining PCIe 4.0 performance over long distances without changing the motherboard technology or using costly retimers.

As cloud computing and deep learning accelerators drive faster advances in the PCIe roadmap, existing hardware designs cannot support the higher speed signals over the same distances. The PCIe 1.0 specification allowed signals to travel as much as 20 inches over traces in mainstream FR4 boards, even while passing through two connectors.

In contrast, today’s quicker 16 GT/s PCIe 4.0 signals will peter out in under six inches and without going over any connectors. In today’s designs, PCIe 4.0 signals can only travel three to five inches, requiring costly redesigns, moving to MEGTRON 6 and adding a retimer for increased distance.

The PLDA and Samtec solution demonstrates an alternate approach using optical fiber (330 feet) or Twinax Flyover™ Systems (10 inches) to deliver PCIe 4.0 x4 with no significant loss of bandwidth.

Demo Overview and benefits:

  • PLDA’s demo shows a system running at 16 GT/s and displaying relevant throughput and latency measurements. The demo result shows the bandwidth is not impacted by distance when using copper or optical fibers.
  • By using optical fibers, PLDA and Samtec demonstrate that PCIe 4.0 can be used for remote applications (e.g. EMI sensitive environments)
  • By using passive Twinax Flyover™ Systems, PLDA and Samtec show a differentiated and affordable way to design a PCIe 4.0 platform. Using retimers, if you can find them, could cost between $15 to $25 for 16 lanes of PCIe 4.0 at 16GT/s, plus an additional $300 for updating the motherboard PCB to MEGTRON 6. (Cf Rick Merrit article: )

For more information or to discover how the PLDA and Samtec approach could work for your next PCIe 4.0 design: