Will these two cards work in crossfire?

[KreitzAIC12]

I own this card....(SAPPHIRE 100354OC-2L Radeon HD 7870 GHz Edition 2GB 256-Bit)
http://www.newegg.com/Product/Product.aspx?Item=N82E16814202025

Will it work in crossfire with this card??...SAPPHIRE 100364-4GL Radeon R9 270X 4GB 384-Bit
http://www.newegg.com/Product/Product.aspx?Item=N82E16814202049

I've heard mixed things already about CF'ing the 7870 with R9 270's/270x's. Something about they have to have the same GPU core??? Will the 4gb/384 bit of the 270x be an issue working with my 2 gb 256 7870? Also the 270x 4gb has 2048 shaders, where my current 7870 has 1280.

 

[06yfz450ridr]

270x doesnt have 2048 shaders it has 1280 as well you will be fine since its the same card the specs you have are from a 280x/7970 which will not work with a 7870

i though they did make a 4gb 270x but is will still have the same shader count and memory bus. it looks like the specs on newegg arent correct.

I cant even find that card on sapphires site

 

[Novuake]

Nope, you won'y be able to crossifre those cards.

 

[06yfz450ridr]

http://www.newegg.com/Product/Product.aspx?Item=N82E16814202050&cm_re=270x-_-14-202-050-_-Product

might as well just grab a regular 270x if you did get a 4gb card 2gb wouldnt be usable anyways if you could crossfire them

 

[KreitzAIC12]

Is there any benefit to using 2x 2gb cards vs a single 4 gb card? I'm wondering because if 2 Gb of vram cant be used when in crossfire 4gb+2 gb - 2gb = 4 total. In crossfire the two cards technically running twice the memory bus? So 512 bit? Same with shaders, do I get 2560 using the two cards?
Reason I ask all this is because, say there's a game that doesn't support multi GPU's, I could turn off the lesser card and use the single 270x and it should maintain it's 4gb holding. Then I play a different game that DOES support crossfire, then I would turn the lesser card back on, I would have 4gb total still, but twice the mem bus and shaders? That last part about the mem bus and shaders is what I mostly don't know too much about.

 

[06yfz450ridr]

most games that support crossfire /no profile you can use a known working profile from another game in ccc, i play never winter and it has the same issue, i use the bf4 profile and xfire works great.

a 4gb 270x isnt worth it, 2 2gb cards will do just fine,