PCIe显卡，16对 Receive 信号是闲置的吗？

Quantum_

1. x16 的显卡， 共有HSI(0)n/p ~ HSI(15)n/p 16对Receive信号（显卡到CPU）.
, H1 _6 m/ _' u7 a7 r. P  ]2. 显卡只是一个输出设备，只接收CPU的输出， 并不需要与CPU高速交互。
3. 那么， 第1点描述的16对线， 是否就一直是闲置的？ (这么浪费，有点不可思议！特发此问）

**参考文书：
https://en.wikipedia.org/wiki/PCI_Express

9 R# K) J- D5 F+ s谢谢！

超級狗

PCI Express Basics and Background

Quantum_

Dear Super
. g" ~' \9 W5 u# `+ |  Z* NI still can't understand what happened to PCIe receiver signals to make them transmit signal from Device to Host, after reading your attachment carefully.
6 q& z5 _3 [# E; o- QDo you mean that the answer of my question is concluded in the chapter below?
"Credit-based flow control is point-to-point based, not end-to-end, "
4 m. y; R8 v% @, G! G9 Z3 J! O7 j* N" Kor
"Split Transactions"


0 E9 o" y2 q* ?7 V& r3 i. ^Do you have any other stuff for a rookie EE to learn about the PCIe Dispaly Card.
- U+ S" J) G; J/ X; X
Thanks very much.


* ~4 R6 ~0 @; D; w2 q+ N

ykwym

PCIe的有些包发出来是需要接收端发信息回去，确保包是一定被收到的。so。。。