Can I use a 10 GbE (RJ45) NIC with a x8 PCIe 2.0 connector in a x4 PCIe 3.0 slot and get full speed? (alien.top)

submitted 2 years ago by [email protected] to c/[email protected]

5 comments fedilink hide all child comments

I'm thinking of getting a 10 GbE NIC for my computer, but I only have a spare x4 PCIe 3.0 slot. The NICs with x4 connectors are all around $90-100.

I can get an older Intel one for under $40 but they all come with x8 PCIe 2.0 connectors. I can physically plug them into my x4 PCIe 3.0 slot because it has an "open back", so they will fit and I know they will still work.

But the question is - will I get full speed. x4 PCIe 2.0 should be able to do around 2 GB/s, so even after overheard it should be able to deliver the ~1.2 GB/s that is 10 gigabit. But is it wired in a way that it can do that is the question.

What do you think, should I try it?

top 5 comments

sorted by: hot top new old

[-] [email protected] 2 points 2 years ago

It'll only run as if it was in a 4x PCIe 2.0 slot, so 2000MB/s.

[-] [email protected] 1 points 2 years ago

Ok so it'll be fine then?

[-] [email protected] 1 points 2 years ago

The PCIe spec says you should be anyhow

[-] [email protected] 2 points 2 years ago

It may be worth trying, but it's possible/likely you won't get full speed out of it. Your card will only support PCIe 2, so, your system will have to downgrade those channels to be compatible.

[-] [email protected] 1 points 2 years ago

It COULD work but the final results would depend on your MoBo and the drivers playing nicely.

this post was submitted on 16 Nov 2023

1 points (100.0% liked)

Home Networking

321 readers

11 users here now

A community to help people learn, install, set up or troubleshoot their home network equipment and solutions.

Rules

Please stay on topic.
Please use the search function to look for keywords related to what you want to ask before posting since most common issues have been answered.
No Ads. This community is for support and discussion. Ads and self promotion are not welcome here.
No product reviews or announcements. If you have a question about a product, be specific about what you want to know.
Be civil. Don't be a jerk. Not being a jerk is surprisingly easy.
No URL shorteners. URL shorteners tend to hide the real use of a link. For this reason, please use normal links, even if they're long.
No affiliate links.
No gatekeeping. With profession shall come professionalism. Extend help without judging others for their ignorance. The same goes for downvoting of comments or posts for "stupid questions" or not being as knowledgeable as others.

founded 2 years ago

MODERATORS

[email protected]