This live product demonstration from OFC 2022 emulates real-world AI system architectures, based on the PECFF form factor. It incorporates a PECFF backplane with PECFF add-in-cards.
Matt Burns, Technical Marketing Manager at Samtec, walks us through the demonstration. He explains that we’re comparing the performance of two backplane architectures.
The first is a traditional rigid PCB backplane, with Samtec HSEC6-DV edge card connectors interfacing with the PECFF add-in cards.
The second is a flexible cable backplane architecture using a .6 mm pitch GC6 Samtec Flyover®cable assembly. Samtec Flyover cable systems are commonly used in mid-board applications, but they also allow designers to go from one board to another as a flexible backplane architecture within a rack, as well as being used as a rack-to-rack interconnect.
This cable backplane design simplifies the PCB stack-up while achieving higher performance targets.
Let’s look at the two signal paths and compare the results.
Both designs begin with a Synopsys PCIe 6.0 PHY generating 64 GT/s PAM4 differential signals. These signals travel to a Samtec Bulls Eye® (BE70A) high-performance test point system, through 20” of low-loss coax cable, to Samtec 2.40 mm precision RF connectors on the backplane.
Let’s look at the rigid backplane first. That signal travels from the SMA to and through a Samtec HSEC6-DV micro-edge card connector, to the rigid backplane. It then travels through 9” of backplane PCB, to another HSEC6-DV edge card connector, to a second add-in-card, then back to the Synopsys device for analysis. The total signal path is about 1.4 meters.
The second signal, to the cable backplane, travels from an SMA on the rigid backplane, through about 4 1/4” of PCB trace, to a Samtec HSEC6 edge card connector, which mates to Samtec’s new GC6 cable connector.
The signal then routes through 20” of 38 AWG Eye Speed Twinax cable, through a second HSEC6 connector on the backplane, and back to the Synopsys PHY for evaluation. The total signal path on the cable backplane is about 1.75 meters.
The signal integrity performance along the signal chains are impressive. The signal channel loss is approximately 30 dB. Over the channel we see a pre-FEC BER of e-8 for the cable backplane solution, wide-open eyes, clean histograms, and true PCIe 6.0 performance.
The performance of the rigid backplane system is similar, with a pre-FEC BER of e-7.
This demonstration shows the full interoperability of Samtec Flyover cable technology and high-performance interconnect solutions, with standard off-the-shelf PCIe 6.0 solutions from Synopsys. It includes PCIe 6.0 applications typically found in AI, machine learning
This demonstration shows that Samtec Flyover technology and high-speed interconnect systems can effectively operate in 64 GT/s platforms, including PCI Express 6.0 AI, ML, and HPC applications.
If you have any questions about this demonstration, please contact us at SIG@samtec.com.