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）.
. C% ~4 k9 |; M( ~0 T- _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：
1 P/ E4 P# w: r- k0 w& v; Phttps://en.wikipedia.org/wiki/PCI_Express

# `9 a4 o% V; {" k3 u7 }谢谢！

超級狗

PCI Express Basics and Background
; k: C; M# \0 a! ]

Quantum_

Dear Super
I still can't understand what happened to PCIe receiver signals to make them transmit signal from Device to Host, after reading your attachment carefully.
Do 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, "
1 V3 w) W  Z* {" m2 s# Nor
% O" ]  [5 ?, X  B- y9 e8 T& k"Split Transactions"

6 b# p: l3 I- x( I! L6 K
Do you have any other stuff for a rookie EE to learn about the PCIe Dispaly Card.

" r' B3 C6 N% tThanks very much.
/ P: z1 S5 J4 W6 _5 h

% q4 S$ B1 T$ D$ G9 g  N0 s

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。。。

alexfu1984

就需要这个东东，好就一个字