Did AMD Based Graphics Cards Change The Number of PCIe Lanes Used?

You all have probably heard this before but I couldn't find it searching.

I was looking over video cards and noticed that AMD flavored graphics cards are using 8 lanes in a 16 lane PCIe slot.
My old XFX Radeon R9 380 PCIe 3.0 from years ago is using 16 lanes in my recent build. I'm wanting to return my R9 card back to my old PC and get a new card for my recent build but nearly all AMD based cards are using only 8 lanes.

My recent build has supports PCIe 4.0 x16. For example one card I looked into is the Radeon RX 6600 8GB GDDR6 PCIe 4.0 but It uses 8 lanes also.

Or does PCIe 4.0 graphics cards doesn't really need all 16 lanes?

Oh! Ok. Thanks for the info!

Turtley said:

Oh! Ok. Thanks for the info!

Get GPU-Z

Run it, and click the little question mark on the right edge, and start the Render test.
The Render test will show you the maximum Bus Interface your vid card and motherboard will support.

TechPowerUp GPU-Z v2.54.0 Download | TechPowerUp

The max. I can get is PCIe x16 3.0

Ghot said:

Get GPU-Z

Run it, and click the little question mark on the right edge, and start the Render test.
The Render test will show you the maximum Bus Interface your vid card and motherboard will support.

TechPowerUp GPU-Z v2.54.0 Download | TechPowerUp

The max. I can get is PCIe x16 3.0

I do use CPU-Z from time to time. Here's the R9 in my recent build.


I was comparing the Sapphire Pulse Radeon RX 6600 8GB GDDR6 and the Sapphire Pulse AMD Radeon RX 6700 XT 12GB GDDR6 cards. Both cards are PCIe 4.0.
The RX 6600 uses 8 lanes where the RX 6700 XT uses 16 lanes according to the specs.

I wonder if one can tell the difference between the two cards?

Thanks for the tip though.

Turtley said:

I wonder if one can tell the difference between the two cards?

As I said... GPU-Z will tell you the difference. Put one card in the comp, and run GPU-Z. Click the little "?" to run the Renderer, then take a screen shot.
Then do the same, but with the other card installed.

They will probably both say PCIe x16, which means both cards are running in x16.

Ghot said:

...They will probably both say PCIe x16, which means both cards are running in x16.

Even the less expensive one using 8 lanes?

Turtley said:

Even the less expensive one using 8 lanes?

I'm NOT an AMD card guy. But I do know that GPU-Z has the answer. You can read all the stuff you want on the web... but GPU-Z will tell you for sure.

Ghot said:

I'm NOT an AMD card guy. But I do know that GPU-Z has the answer. You can read all the stuff you want on the web... but GPU-Z will tell you for sure.

Ok. Thanks for your assistance!

Turtley said:

Ok. Thanks for your assistance!

The R9 380 is PCIe x16 3.0
The RX 6600...








ALL the AMD cards...
List of AMD graphics processing units - Wikipedia





BUT.... the "version" matters too...
So, a PCIe x16 v3.0 is the same bandwidth (speed), as a PCIe x8 v4.0

How Many PCIe Lanes Does a GPU Use? (Complete Guide)