PCI Express x8?

[Pixel Eater]

Will a motherboard with a second PCI express slot lowered to x8 effect the second card's performance? Assuming it's at least an 8800 GT if not better.

I'm trying to decide rather I need a board that supports x16 * 2 or not.

 

[Domini]

no pci-e card right now uses the full 8x bandwidth. you will be fine.

 

[Blahman]

there is a small performance hit with 8800GT-class cards and up, probably about 5-10%.

 

[S-B]

there is a small performance hit with 8800GT-class cards and up, probably about 5-10%.

Depends on the application. Another member here pointed me to a benchmark of several apps, and on some there was no difference, while on others (like Quake Wars), the game took a significant hit.

Go dual x16 if possible, but if you absolutely must, x16/x8 will suffice.

 

[TerraPhantm]

If it's PCIe 2.0, there's nothign to worry about, PCIe 2.0 x8 has the same bandwidth as PCIe 1.0 x16

 

[ALL4AMD]

If it's PCIe 2.0, there's nothign to worry about, PCIe 2.0 x8 has the same bandwidth as PCIe 2.0 x16

umm wat? did u mean PCIe 2.0 x8 has the same bandwidth as PCIe 1.0 x16?

 

[wadec22]

pci-e 2.0 at 8x does have the same bandwidth as pci-e 1.0 x16. pci-e 2 doubles the bandwidth of 1. the 8x and 16x simply refer to the number of open pci-e lanes to transfer data on.

tomshardware.com has a good write up on this. if you game at 1920x1200 or higher and use a something like g92 in sli or gx2 it is a benfeit and will also be on it's successors. at lower rez, no big deal.

 

[TerraPhantm]

oops... yea I meant 1.0; I edited the post to fix it

 

[ALL4AMD]

oops... yea I meant 1.0; I edited the post to fix it

its ok we all make mistakes.