Replay buffer size – PCIe provides CRC protection for all Transaction Layer Packets (TLPs) and specifies packet replay mechanism if CRC errors are detected by the receiver. All TLPs are stored in an ...

Therefore this will affect latency of transmitting/receiving a TLP over the link. Maximum Payload Size (MPS) A PCI Express device can support a maximum payload size per TLP from 128 bytes to 4 KB.