AI平台中PCIe 5和PCIe 6的混合使用：优势与挑战.pdf

1、Mixing PCIe 5 and PCIe 6:System Design ChallengesAstera LabsMixing PCIe 5 and PCIe 6 System Design ChallengesCaleb ShetlandApplications Engineer/Astera LabsSERVERCapture the bandwidth benefit of PCIe 6 now.No need to wait for the whole ecosystem to move to PCIe 6.Leverage existing install base of PC

2、Ie 5 equipment.Enjoy wide choice,rich inventory,short lead times of mature PCIe 5 ecosystem.Future-proof the system design:swap out PCIe 5 components for PCIe 6 when available.Achieve optimal performance by matching total bandwidth across data rates.Benefits of mixing PCIe 5 and PCIe 6Smart Fabric S

3、witchPCIe 5 HostPCIe 6 HostPCIe 5 EndpointPCIe 6 EndpointPCIe 5 EndpointORThere is no“safe road”.Continuing to do what we did in the past is not adequate.Rigorous analysis and thorough system validation are the only way to navigate the PCIe 5 to PCIe 6 change successfully.When designing for mixed-mo

4、de PCIe 5 with PCIe 6,system designers need to pay more attention to EP feature set and requirements than previously.PCIe 5 host with both PCIe 5 and PCIe 6 EPs will remain a common configuration for multiple design cycles.Today well highlight 3 examples of areas where we see a need for system desig

5、ners to focus.Unprecedented change from PCIe 5 to PCIe 6FM:Requester segment in OHC-C.FM:Completer segment in OHC-A5.Segments dont exist in NFM.officially.PCIe 5 hosts dont know about PCIe 6 segment definition.However,in some cases they have their own,potentially incompatible,implementation of segme

6、nts.Legacy self-enumerating solutions need extra scrutiny.Consider the case where a PCIe 6 switch is self-enumerating.System designers should PREVENT PCIe 6 EPs from capturing a segment ID if the host is PCIe 5.Segmentssystem designers should focus on:Ensuring that PCIe 6 devices are prevented from