Please explain why PCI-E has this behaviour

[ImNotNeko]

I always thought that any PCI-E card would work on any PCI-E slots.

There would be consequences like if you put an RTX a6000 in a 4x slot you'd lose some performance.

 

But yesterday, I learned that some 4x card straight up doesn't work at 8x or 16x slot.

For example Titan Ridge (rev 2.0) REQUIRES a 4x PCI-E slot.

 

What makes it so that this card doesn't work in other slots?

Every other add in cards I use that requires a 4x bandwidth works perfectly fine on a 8x or 16x slots.

[HanZie82]

13 minutes ago, ImNotNeko said:

I always thought that any PCI-E card would work on any PCI-E slots.

There would be consequences like if you put an RTX a6000 in a 4x slot you'd lose some performance.

 

But yesterday, I learned that some 4x card straight up doesn't work at 8x or 16x slot.

For example Titan Ridge (rev 2.0) REQUIRES a 4x PCI-E slot.

 

What makes it so that this card doesn't work in other slots?

Every other add in cards I use that requires a 4x bandwidth works perfectly fine on a 8x or 16x slots.

I dont think the Titan Ridge (rev 2.0) is just another PCIe card. It needs specific motherboards to even function properly.
Here's a list with supported motherboards: https://www.gigabyte.com/nl/Motherboard/GC-TITAN-RIDGE-rev-20#sec04

[Helpful Tech Witch]

Sometimes it's up to the motherboard. A 4x usually works in a 15x, but sometimes it doesn't.

But doesn't Titan ridge need specific motherboards?

[Pixel5]

there are no standard PCI-E cards that require a specific slot like 4x and wont function in a 16x slot.

The card has no way to know in which slot it is, a 16x slot and a 4x slot will make the exact same contacts to the card.

 

the titan ridge is not a standard PCI-E card and requires a specific motherboard wich apparently has some special sauce that they only put on the 4x slot.

[ImNotNeko]

14 minutes ago, HanZie82 said:

I dont think the Titan Ridge (rev 2.0) is just another PCIe card. It needs specific motherboards to even function properly.
Here's a list with supported motherboards: https://www.gigabyte.com/nl/Motherboard/GC-TITAN-RIDGE-rev-20#sec04

uhh yeah kinda...

It also works with other motherboards with supported connector.

 

My Aorus X299 Gaming 9 is not on their support list but it works flawlessly out of the box.

 

Only requirement is 4x slot and TB3 connector.