Requirements Double When X-Firing

[wildernesshobo]

Hello,

video card and cpu:
Radeon HD 7870 GHz X-Fire
Haswell i-5 4670k 3.4 GHz
(let me know if more info is needed)


I recently bought a second video card to crossfire with the one I've already got. I thought it would double graphical performance and increase overall fps, but I've been noticing that there is no difference except in one single game.

I was playing GTA5 and I noticed that the performance and settings are exactly the same as when I was using one card. The only difference was a minor rise in fps (5-15). I was playing on high/very high at 50ish fps, but now I'm playing on the same settings at 60ish fps. I can't increase the settings much (in any game) because the requirements have doubled since installing the second card.

I'll start with the game it helps with; Far Cry 3, I was replaying it when I installed the second card. Prior to installation I was getting a solid 50 fps on minimum (with minor lag spikes at times), to 100+ on ultra with no lag spikes at all. Only being able to play on minimum with far cry 3 is not right for my rig, but I just went with it.

Now for the weird part; I've only got pictures of GTA5, because this is the only game in my library that displays the settings like this. When I only use one card, minimum settings uses just over 1GB, normal about 1.5, and I don't set it to ultra because it requires 3 GB, which I don't have on the single card. Now I turn on crossfire thinking it will get ultra no problem, well now minimum settings uses just over 2 GB, normal uses 3, and I can't set it to ultra because it uses almost 5, when I only have 4 GB between the two cards.


I'm fine with playing on high settings, but I spent $200 on that second card to get some real use out of it, and I'm not getting that right now.

Any help would be greatly appreciated,

thanks,
-wildi

(I don't know how to upload the pictures, sorry)

 

[jerdle]

Well VRAM doesn't stack on the two cards, the same data is copied across both....

 

[Dragos Manea]

if one card has 3gb adding one mroe card doesnt mean you have 6 gb, you still have 3 gb, as jerdle said, same data is copied on both. Using crossfire/sli doesnt give u 2x performance, most games are very bad optimized for sli-cross and you will see a 15-25% improment if you are lucky, if not the game doesnt support at all cross-sli and you will have same performance as a single card. Best way to check if your setup works correctly run 3d mark, it is for sure optimized for cross-sli.

 

[wildernesshobo]

Thanks, I'm not the most computer savvy person, I was told that X-fire greatly improves performance. So I basically wasted $200?

 

[wildernesshobo]

Well VRAM doesn't stack on the two cards, the same data is copied across both....

Thanks.

 

[Dragos Manea]

Thanks, I'm not the most computer savvy person, I was told that X-fire greatly improves performance. So I basically wasted $200?

Not really, you can benefit from it but not in all games.

 

[wildernesshobo]

Thanks, I'm not the most computer savvy person, I was told that X-fire greatly improves performance. So I basically wasted $200?

Not really, you can benefit from it but not in all games.

Ok thanks.