Crossfire question

sadness20

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Jun 22, 2007
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If a buy mother board with crossfire support 1 PCI express Slot 16X second PCI express Slot Slot 4x.

I currently own a 1950xt 256mb gpu if i get an 2900xt 512mb gpu is crossfire going to work with my old 1950xt card? or i need 2x 2900xt?
 

justjc

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Jun 5, 2006
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Actually they don't allways have to be identical, however I doubt the X1950XT will work with a HD2900XT. ATi hasn't updated the comparison charts, so none of the new cards are on it, but you can have a look at what your old card can be paired with at http://ati.amd.com/technology/crossfire/charts.html

About setting two HD2900XTs in crossfire I must admit I don't see the point, unless offcause you play on a >30" screen with a very high resolution. Best bet is to get one and see if you really need another.
 

emp

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EDIT: I stand corrected, but still pretty pointless if you ask me to pair your card with a lesser card, I'd prefer using identical cards, allows for less problems on an already cumbersome area (dual card setups).
 
Just curious, if the OP buys another 1950xt, what kind of motherboard would be better for Crossfire, P5W-DH (8x+8x) or GA-P35-DQ6 (16x+4x) ? In general, which combination works better? I am guessing the 8x+8x, but I haven't found any serious proof yet.
 

Rage_3k_Moiz

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Jul 27, 2007
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Why go Crossfire in the first place? Your current X1950XT is a good enough card on it's own. If you really want a faster card, get an 8800 series card from NVIDIA or a single HD 2900XT instead. Crossfire needs too much power and proper cooling in place to work effectively enough. I used to have a Crossfire righ with two X1900XTXs and I installed watercooling just for them. Not to mention the fact that two cards are generally louder than one. Also, Crossfire only proves it's worth at ultra-high resolutions above 1600x1200. So unless you're willing to\have a monitor capable of very high resolutions, a PSU that can handle the two graphics cards and adequate cooling to prevent your PC from turning into a giant heater, I would advise against it.
 

rammedstein

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highend p35 boards perform equally to the highend 975x boards for crossfire regardless of the difference in link width because the p35 chipset handles the crossfire connection better than the 975x board to make up for the lack of bandwidth to the 2nd card, also, ati cards don't get effected in instability in overclocking the pci-e frequency for some reason, so personally i would get a 975x board and overclock the pcie freq to 150, giving you the equiv of 12x 12x.