Motherboard PCIe capabilities

[Mycielski]

Hi!

 

I would like to ask you some questions about PCIe lanes.

I have an old ASUS P5QC with P45 chipset, which claims only to support x16 PCIe.

I use a GPU in the PCIe x16 slot, but also a WLAN card in an PCIe x1.

My question is, do this config (PCIe x16 and PCIe x1 simultaneously) hurts the performance of the GPU? Does this setup means, that utilizing that x1 slot, reduces the possible performance (bandwidth) of the GPU?

Does this even throws the GPU back to x8 mode, or something like that?

 

Thanks in advance for the replies and help!

[Andrew279cz]

2 minutes ago, Mycielski said:

Hi!

 

I would like to ask you some questions about PCIe lanes.

I have an old ASUS P5QC with P45 chipset, which claims only to support x16 PCIe.

I use a GPU in the PCIe x16 slot, but also a WLAN card in an PCIe x1.

My question is, do this config (PCIe x16 and PCIe x1 simultaneously) hurts the performance of the GPU? Does this setup means, that utilizing that x1 slot, reduces the possible performance (bandwidth) of the GPU?

Does this even throws the GPU back to x8 mode, or something like that?

 

Thanks in advance for the replies and help!

Utilizing that 1x PCIe lane should not hurt the performance of your gpu. Even current "mainstream" Intel CPUs have just 16 PCIe lanes.

The only thing that could lower the performance of your gpu is the gen of the lane. I think this one should be gen 2, so it should not matter. (it does if you are using very high end GPUs)

[SkyHound0202]

No it does not.

The x16 slot is a native PCIe slot from CPU, while the x1 slot is from the chipset.

[Mycielski]

Andrew: Yeah, it's only PCIe 2.0, and I use it with a GTX 660, so I guess it is nowhere near "high-end". Thanks for the response, then I will stop worrying.

 

SkyHound: Well, according to THIS picture, I guess the PCIe x16 slot is handled by the NB(P45) and the PCIe x1 lanes by the SB(ICH10/R). In this generation the memory controller as well as PCIe handling was not integrated to the CPU, that's for sure.

[Mycielski]

6 minutes ago, VegetableStu said:

Even so the x16 lane bus on the northbridge would be closer to the CPU, than the other IO and PCIe lanes on the southbridge via DMI ._. (also note that the RAM is on the northbridge as well)

That's true, thats why I posted the image as well.