X16 vs dual x8?

[LordWolf]

Already looking at this page:
http://www.tomshardware.com/reviews/pcie-geforce-gtx-480-x16-x8-x4,2696-3.html

Now to be direct.

What is the difference? Is it the amount of 'bandwidth' available to each card? Unless I'm told otherwise, I'm going to presume it is and ask this:
Using multiple monitors (two, sometimes a third when using HDMI to the TV), is there a huge/noticeable difference when using two cards at x8?

I'm looking to upgrade my current system.
http://www.tomshardware.com/forum/353512-31-some-advice-opinions

 

[fantastik250]

It will depend on the version PCI-E slot (1.0, 2.0, 3.0) and the mode (x4, x8, x16) not size.

You won't see any performance loss on a PCI-E 3.0 Slot at x8, or a PCI-E 2.0 at x16. Any lower you will start have performance loss with the top end cards.

This benchmark should help.

But for mid-range cards you will see less performance loss. And for low-range, practically no performance loss.

Hope that helps

 

[LordWolf]

It will depend on the version PCI-E slot (1.0, 2.0, 3.0) and the mode (x4, x8, x16) not size.

You won't see any performance loss on a PCI-E 3.0 Slot at x8, or a PCI-E 2.0 at x16. Any lower you will start have performance loss with the top end cards.

This benchmark should help.
http://tpucdn.com/reviews/Intel/Ivy_Bridge_PCI-Express_Scaling/images/perfrel.gif

But for mid-range cards you will see less performance loss. And for low-range, practically no performance loss.

Hope that helps

Looking at a 440 and a 210/220 (I think it's a 220 but may be a 210) on a PCI-E 2.0 or 2.1 system.

Am I correct though that it's basically the amount of 'bandwidth' available to each card at a given moment?

 

[fantastik250]

That is correct, it's the amount the PCI-E slot can deliver. But for the cards you mentioned, won't max out the bandwidth.

 

[LordWolf]

Best answer selected by LordWolf.

 

[DM186]

^+1
He said it all and it doesn't matter how many monitors there are. The x 16 x 8 x 4 is the speed in which info is pushed through the PCIe slot and the 1.0, 2.0, 2.1, and 3.0 is the multiplyer that you use on how much band width you are moving.

Lets say x 16 is 4000 to 8000 MB per second and I put it in to a 2.0 slot now the 8000 MB per second now becomes 16000 MB per second. Anyway thought I would share this and Good luck to you.

 

[LordWolf]

That is correct, it's the amount the PCI-E slot can deliver. But for the cards you mentioned, won't max out the bandwidth.

Thanks. So I take it that it wouldn't make a noticeable difference for me, that's what I was looking for.