Unable to determine PCI-e version in Linux terminal (Ubuntu 18)

Question

I am looking forward to upgrade my desktop GPU. First of all, I need to know what kind of PCIe slot I have. My home desktop is Asus with H81M-E/M51AD/DP_MB motherboard which has 2x single PCIe slots and 1x PCIe-16. I want to determine the version of PCIe-16 slot (2.0 or 3.0).

I did not find this information in documentation of my motherboard.

I have windows 10 and Ubuntu 18 installed. Following one of the many similar SO answers, I've tried the following in Ubuntu terminal (note, that I've used remote ssh connection as I am working on MAC):'

$ sudo dmidecode | grep "PCI"
[sudo] password for misha: 
    PCI is supported
Designation: PCIEX16_1
Type: x16 PCI Express
Designation: PCIEX1_1
Type: x1 PCI Express
Designation: PCIEX1_2
Type: x1 PCI Express

$ lspci -vv | grep -E 'PCI bridge|LnkCap'
00:01.0 PCI bridge: Intel Corporation Xeon E3-1200 v3/4th Gen Core 
Processor PCI Express x16 Controller (rev 06) (prog-if 00 [Normal decode])
00:1c.0 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #1 (rev d5) (prog-if 00 [Normal decode])
00:1c.1 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #2 (rev d5) (prog-if 00 [Normal decode])

For some reason, there is no information about PCIe version. How can I determine the version of my PCI slots?

Thanks, Mikhail

Answer 1

Windows Solution

Have you tried HWiNFO under Windows 10? This tool can often give more comprehensive information than the likes of CPUID, for example. It should be given under the Version header for the PCI Express bus.

I'm aware you're looking for a Linux solution, but if Windows is installed, this can give a clear-cut answer.

Linux Solution

Also, I think you need to run lspci as root, as indicated in the question and answer you linked. Else, the capabilities of the PCIe Bridge are silenced and removed by grep.