Crossfire 6770 vs single 6950

hambone6

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Hey, I'm looking at graphic cards for my first build and I'm planning on running triple 20" monitors in eyefinity with a res of 4800x900.


This is the mobo I think I'll be getting: MSI 870-G45 AM3 AMD 770 ATX
http://www.newegg.com/Product/Product.aspx?Item=N82E16813130290


The 6950 has 2gb gddr5 memory, Its the SAPPHIRE 100312-3SR Radeon HD 6950 Dirt3 Edition
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102945


The 6770 is SAPPHIRE 100338L Radeon HD 6770 1GB gddr5
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102941




About the crossfire, will my mobo with one x16 slot in x16 mode, and one in x4 mode slow this down? Can I put the x4 in x16 mode? Better mobo??

The crossfire would be a little cheaper, but would it be worth the hastle?


Also, I cant seem to find whether or not the mobo or card come with crossfire bridges.




Thanks. Mainly looking for advice here. :)
 

amirp

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the 6950 2gb hands down is the better choice, two 6770 isnt any faster and even in crossfire you'd still only have 1gb of Vram ... and at the resolution you plan on playing you can really use the 2gb the 6950 offers
 

wintermint

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Yes, the x4 will be the bottleneck for the second graphic card. The 6770 is around $120 each before MIR so I'll assume your budget is more of the $240. At that price, I would either go for the 6950 you were considering or a 560 ti. If you want, the 6870 performs really well at high settings.

Other than the x4 bottleneck. Some reasons not to go crossfire is the temperature and heat produce. Driver support are not that great for crossfire compare to single too.
 
I would reccomend going with a 6950.The 2G of RAM the 6950 offers is much better for larger resoultions.And you can always add another 6950 later on.

Actually the x4 slot doesn't slow the card down as much as you'd think.On average, depending on the system, it only slows down about 5-10 fps compared to a x16 slot.

What are your full system specs?(CPU,RAM,etc.)

What is the make/model of your PSU?

Want to make sure the rest of your system won't be a bottleneck or has enough power to run with either choice you choose.
 

hambone6

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Cpu is amd phenom ii x4 955 @ 3.2 GHz (stock), 4gb ddr3 1333 ram, and the psu is antec high current gamer series 620W.
 

hambone6

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So in crossfire if you have two 1gb cards, the pc sees them as one 1gb card with two gpus, not one 2gb card with 2 gpus?
 

hambone6

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Ohh. Thanks for that explanation. I guess I'll go with the 6950, I could always get another and do crossfire with them.

Can you use two different brands for the crossfire? Like have a sapphire 6950 paired with a an MSI 6950?


Thanks again
 
I'm not sure but I beleive if you use a 2G with a 1G they will both only use 1G of RAM.But as I said i'm sure about this.

You can use 2 different brands as long as their from the same series 69xx.Although it's always reccomended to use the same brand.

I think a 6950 2G is a wise decsion.It's good for high resolutions(eyefinity) and when you add another for crossfire it will be way better than a 6770 crossfire.
 



mixing a 1 gig and 2 gig card will result in both cards being seen as 1 gig total, so basically crossfire a one gig and a two gig and you have 1 gig total of vram.

Just like when crossfiring a 512mb 4870 and a 1 gig 4870; you will basically have a 512mb 4870x2
 
Alright.Yah that's what I thought but i had forgotten.

I always reccomend the 2G cards because I know that I would someday like to run eyefinity.Of course that's not the same intention with everyone else but I think it's always good to have it just in case because you never know.
 

amirp

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you guys aren't reading the original post.... he plans on using eyefinity... just buy the 2gb 6950, it is your best choice for what you want to do,

I am pretty sure at that resolution 2gb isn't a gimmick (I could be wrong for some games but i'd much rather have 2gb and 1gb for triple monitor use)