PCIE 2.0 8X bottleneck for 290X/390X?

[Mercennarius]

Considering running crossfire with my 290X with a 390X. Problem is the two 16X slots are to close together so I will have to run one in the 8X slot. It's this a bottleneck?

 

[Deders]

For the most part no, so long as all the data fits into the Vram.

PCIe bandwidth can help in situations like the highest resolution textures in Shadow of Mordor that require 6GB of Vram. My old PCIe2 x16 setup couldn't handle swapping the excess data between Vram and system ram. Now with PCIe3 and the same graphics card (also much faster Ram) I'm getting 60fps with only 3GB of Vram.

Same goes for GTAV and Batman Arkham Knight. I'm able to play with settings that far exceed my Vram limit.

 

[RussianSensation]

Considering running crossfire with my 290X with a 390X. Problem is the two 16X slots are to close together so I will have to run one in the 8X slot. It's this a bottleneck?

This is a none issue for this level of GPU. I would consider the option of selling the 290X and getting a single 980Ti though.

 

[Mercennarius]

This is a none issue for this level of GPU. I would consider the option of selling the 290X and getting a single 980Ti though.

OK so my 290x won't be limited by 8X PCIE 2.0 then?

 

[Deders]

It won't be limited in usual conditions where everything fits in the Vram.

 

[Mercennarius]

It won't be limited in usual conditions where everything fits in the Vram.

OK thanks, is an 8GB card so I should be good I assume.

 

[Deders]

OK thanks, is an 8GB card so I should be good I assume.

Isn't the 290 a 4GB card? If so when it is used in crossfire mode both cards will only be able to use 4GB each. If you find yourself in a situation that using more than 4GB is more desirable than the framerate boost then so long as the 390 is your primary card, you can disable Crossfire and still have 8GB.

TBH I think 4GB will be enough for 99% of games in the near future.

 

[MagnusTheBrewer]

It won't be limited in usual conditions where everything fits in the Vram.

Sloppy programming on behalf of the developers can't be fixed on the user side anyways, see crysis.

 

[Deders]

Sloppy programming on behalf of the developers can't be fixed on the user side anyways, see crysis.

Was mainly talking about situations where I'm able to get away with using over 4GB on a 3GB card due to high PCIe and memory bandwidth. See my previous posts.

 

[Mercennarius]

Isn't the 290 a 4GB card? If so when it is used in crossfire mode both cards will only be able to use 4GB each. If you find yourself in a situation that using more than 4GB is more desirable than the framerate boost then so long as the 390 is your primary card, you can disable Crossfire and still have 8GB.

TBH I think 4GB will be enough for 99% of games in the near future.

Both cards are 8GB.

 

[Deders]

You'll be fine then