In BIOS, does PCI-e "Max Payload Size" affect anything?

[Coldblackice]

I just noticed a setting in my evga x58 BIOS:

"Max PCI payload size"

It's been set at 128 for years, however, it's able to be set at a maximum of 4096.



I found this explanation, however, it doesn't give much, as far as particulars:

http://www.techarp.com/showFreeBOG.aspx?lang=0&bogno=387


Does this setting affect anything? Any pros/cons might manifest from either setting the lowest setting (128) or the highest setting (4096)?

From the link, it suggests I should just set it at the max 4096. Could/Would I see any sort of improvements or differences in doing this?

 

[ru!ner]

The X58 only supports payload sizes of up to 256 bytes so setting it higher will still cap it at 256 (section 5.2.1 of that datasheet).

Any setting higher than 128 will allow the PCIe controller to transfer slightly more efficiently, however it is highly unlikely you will notice any difference.

 

[Coldblackice]

The X58 only supports payload sizes of up to 256 bytes so setting it higher will still cap it at 256 (section 5.2.1 of that datasheet).

Any setting higher than 128 will allow the PCIe controller to transfer slightly more efficiently, however it is highly unlikely you will notice any difference.

Gotcha, thanks.

What if x58 happened to supprt up to 4096 -- might there be any noticeable benefit?

I tried finding the max size a 7950 supports, but couldn't find anything.

 

[ru!ner]

The jump from PCIe 2.0 to 3.0 would have a far greater increase in bandwidth. That said, most tests I've seen show a few fps increase at most going from PCIe 1.0 to 3.0 with a single card.