有没有办法确定特定卡的 PCI Express 连接速度？我插入了三张卡：
两块 Nvidia GTX 480（一块为 x16，一块为 x8），一块 Nvidia GTX 460 以 x8 运行
有没有什么方法，可以通过 C 语言中的函数调用或选项来lspci确定显卡的总线速度？当我只为 CUDA 程序使用其中一张卡时，我想使用以 x16 运行的卡。
谢谢！
注意： lspci -vvv转储出来
对于两款 GTX 480，我没有发现与总线速度相关的任何差异。
03:00.0 VGA compatible controller: nVidia Corporation Device 06c0 (rev a3)
Subsystem: eVga.com. Corp. Device 1480
Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0
Interrupt: pin A routed to IRQ 16
Region 0: Memory at d4000000 (32-bit, non-prefetchable) [size=32M]
Region 1: Memory at b0000000 (64-bit, prefetchable) [size=128M]
Region 3: Memory at bc000000 (64-bit, prefetchable) [size=64M]
Region 5: I/O ports at df00 [disabled] [size=128]
[virtual] Expansion ROM at b8000000 [disabled] [size=512K]
Capabilities: <access denied>
Kernel driver in use: nvidia
Kernel modules: nvidia, nvidiafb, nouveau
03:00.1 Audio device: nVidia Corporation Device 0be5 (rev a1)
Subsystem: eVga.com. Corp. Device 1480
Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Interrupt: pin B routed to IRQ 5
Region 0: [virtual] Memory at d7ffc000 (32-bit, non-prefetchable) [disabled] [size=16K]
Capabilities: <access denied>
04:00.0 VGA compatible controller: nVidia Corporation Device 06c0 (rev a3)
Subsystem: eVga.com. Corp. Device 1480
Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0
Interrupt: pin A routed to IRQ 16
Region 0: Memory at dc000000 (32-bit, non-prefetchable) [size=32M]
Region 1: Memory at c0000000 (64-bit, prefetchable) [size=128M]
Region 3: Memory at cc000000 (64-bit, prefetchable) [size=64M]
Region 5: I/O ports at cf00 [size=128]
[virtual] Expansion ROM at c8000000 [disabled] [size=512K]
Capabilities: <access denied>
Kernel driver in use: nvidia
Kernel modules: nvidia, nvidiafb, nouveau
04:00.1 Audio device: nVidia Corporation Device 0be5 (rev a1)
Subsystem: eVga.com. Corp. Device 1480
Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
Latency: 0, Cache Line Size: 64 bytes
Interrupt: pin B routed to IRQ 5
Region 0: Memory at dfffc000 (32-bit, non-prefetchable) [size=16K]
Capabilities: <access denied>
我看到的唯一区别具体与内存映射有关：
myComputer:~> diff card1 card2
3c3
< Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
---
> Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
7,11c7,11
< Region 0: Memory at d4000000 (32-bit, non-prefetchable) [size=32M]
< Region 1: Memory at b0000000 (64-bit, prefetchable) [size=128M]
< Region 3: Memory at bc000000 (64-bit, prefetchable) [size=64M]
< Region 5: I/O ports at df00 [disabled] [size=128]
< [virtual] Expansion ROM at b8000000 [disabled] [size=512K]
---
> Region 0: Memory at dc000000 (32-bit, non-prefetchable) [size=32M]
> Region 1: Memory at c0000000 (64-bit, prefetchable) [size=128M]
> Region 3: Memory at cc000000 (64-bit, prefetchable) [size=64M]
> Region 5: I/O ports at cf00 [size=128]
> [virtual] Expansion ROM at c8000000 [disabled] [size=512K]
18c18
< Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
---
> Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
19a20
> Latency: 0, Cache Line Size: 64 bytes
21c22
< Region 0: [virtual] Memory at d7ffc000 (32-bit, non-prefetchable) [disabled] [size=16K]
---
> Region 0: Memory at dfffc000 (32-bit, non-prefetchable) [size=16K]
答案1
我尝试过这个：cat /var/log/Xorg.0.log | grep "NVIDIA"
它将显示卡及其所在的 PCI Express 插槽以及该插槽的宽度。例如：
20.502] (II) NVIDIA(0): NVIDIA GPU GeForce 9500 GT (G96) at PCI:1:0:0 (GPU-0)
[ 20.502] (--) NVIDIA(0): Memory: 1048576 kBytes
[ 20.502] (--) NVIDIA(0): VideoBIOS: 62.94.1f.00.8a
[ 20.502] (II) NVIDIA(0): Detected PCI Express Link width: 16X
[ 20.502] (--) NVIDIA(0): Interlaced video modes are supported on this GPU
[ 20.502] (--) NVIDIA(0): Connected display device(s) on GeForce 9500 GT at PCI:1:0:0
[ 20.502] (--) NVIDIA(0): Samsung SyncMaster (CRT-1)
[ 20.502] (--) NVIDIA(0): Samsung SyncMaster (CRT-1): 400.0 MHz maximum pixel clock
答案2
这是一个非常古老的问题，但正确做到这一点的方法是运行
sudo lspci -vv
对于每个 pci-e 设备，它都会列出 LnkSta，它会告诉您速度为 _ GT/s、Width x1。它还列出了 LnkCap，即链路容量。
2.5 GT/s = PCI-e gen 1，5 GT/s = PCI-e gen 2，8 GT/s = PCI-e gen 3，宽度为通道数。