PCI-E 2.0 x4 Crossfire

[Noyu]

So I plan on buying an ASUS H97-M Plus MoBo.

It is clearly specified that it has 2 x16 slots but the other one runs on is PCI-E 2.0 and runs x4 only. Hence, crossfire capability (no SLI).

Does this affect crossfire performance? By how much?

Im currently comparing a Zotac AMP! 960 with Sapphire R9 380 (both 4GB).

And im trying compile pros and cons. So, if possible, a good pro for the R9 380 would be crossfire-ing instead of buying a new card.

[Chris_R.]

Yes it affects CrossfireX performance.

 

You need two even lanes for example 2 x16 lane slots. Once you corssfireX those they become 2 8x lanes I have been told.

 

So in your case you technically and ideally need 4 16X lanes.

 

So if you are using a 4x lane once you crossfireX you will have three going at 8X each and then a third going at what 4X or even 2X?

 

I just know that for SLI or CrossfireX its best to stay away from 4X lanes. (or at least that's how it used to be. CrossfireX in my opinion is not worth it at all right now.)

[Arwanell]

it's fine

you will lose about 10% performance with x4 PCIe

 

note that the Intel mobos with dual x16 PCIe are 200$+ at least

[Noyu]

Yes it affects CrossfireX performance.

 

You need two even lanes for example 2 x16 lane slots. Once you corssfireX those they become 2 8x lanes I have been told.

 

So in your case you technically and ideally need 4 16X lanes.

 

So if you are using a 4x lane once you crossfireX you will have three going at 8X each and then a third going at what 4X or even 2X?

 

I just know that for SLI or CrossfireX its best to stay away from 4X lanes. (or at least that's how it used to be. CrossfireX in my opinion is not worth it at all right now.)

For my case, I'm only limited to 2 GPUs.

 

Soooo, AFAIK, I need a 16x lane and a 4x lane (but ofc, both on are 16x slots) (as a minimum). This will then run crossfire on x4/x4..

 

So I don't understand what you're saying here. Please explain again.

 

it's fine

you will lose about 10% performance with x4 PCIe

 

note that the Intel mobos with dual x16 PCIe are 200$+ at least

Hmm. Since Crossfire now uses PCIe for communication between GPUs (no more Xfire bridge), isn't it important to get AT LEAST a x8 PCIe?

[Arwanell]

For my case, I'm only limited to 2 GPUs.

 

Soooo, AFAIK, I need a 16x lane and a 4x lane (but ofc, both on are 16x slots) (as a minimum). This will then run crossfire on x4/x4..

 

So I don't understand what you're saying here. Please explain again.

 

Hmm. Since Crossfire now uses PCIe for communication between GPUs (no more Xfire bridge), isn't it important to get AT LEAST a x8 PCIe?

that's what people told me when i asked to crossfire 2 390's

but i didn't, i'll wait another year for new cards to come out