Questions about crossfire & x2 with compatible motherboards

silnox

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Oct 3, 2008
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Hi all and thanks for reading.

I'm thinking about a new PC and I'm confused with some stuff.

1º When you use two 4870 single cards in crossFire (with intel cpu) you need a motherboard with (x38,x48,i780,i790) because with P45/P35 or others one card will not work as fast as can because is a 16x/8x crossfire.

It's true? or it's not? maybe that happens only when u use two 4870 X2 cards???

2º About problems with E8400 and some motherboards where can i find a list with compatible mothers??? It's real that all the issues disapears with new firmwares or maybe not all ???

3º If u use e8400- 3.000Mhz then the memory u need without oberclok is one faster than 666Mhz??
3000*2/9 = 666,6666.

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Those problems i got because Im thinking a new rigg with E8400 + mobo with crossfire (its really expensive about 2x the price of one with other chip) + 4870 1Gb or 4870 x2 (im not sure yet .. too much money).

I want the mobo with Xfire because I will wanna buy nextyear another 4870 or 4870 x2. Soo then no game will beat me xD ...

PD: Sorry about my horrible english.
 
The i780, i790 chipsets are nVidia, they only support SLI with 2 or more nVidia GPU's, they will NOT work for Crossfire.

For the GPU's you are considering, get a Crossfire board that runs 2 cards both at 16x. Yes, they are more expensive, but with the high end cards you are considering, it would be worth it.

Buy 800mhz, or PC6400 memory, if you plan on overclocking, and even if you don't, memory is cheap.

If you are not afraid of overclocking, buy a quad core. Tight budget, it is still hard to beat a q6600, will overclock easily to the speed of the 8400.
If you have a little more to spend, get a Q9450, it will easily overclock to 3.0ghz as well.
 

stoner133

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Mar 11, 2008
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Make sure the motherboard you choose supports CrossfireX if you plan on running two 4870X2 cards. A Crossfire board only supports two GPU's while CrossfireX supports four GPU's.
 

silnox

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Oct 3, 2008
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Thanks jitpublisher ... I make a mistake writing 780i or 790i they are nvidea and i know...

About Q6600 it is really worse in games than e8400. and bigger q9xx r really expensive. I will not overclok soo i prefear e8400.

There are a lot of chips that can crossfire p38 or p48 but they do one-> 8x and one-> 16x. I know some cards works in real 16x but other ones dont work that way. That's why im asking about Xfire with singel 4870 because i don't know if is one of them.

Stoner I'm asking wich chips can run 4 GPUs ... and wich one can run 2 GPUs... Now I think maybe two single cards 4870 will work nicely in a chip P45 because cards only use 8x ... but I dont know that.

Thank you guys, this forum is really nice becuse ppl really helps.