Planning Crossfire? You need to know this.

[eliasuk98]

The observing ones among you immediately notice that there will be no XTX Crossfire card, this is correct. If you want to go Crossfire on the 1900 then that XT is the only solution you'll have. Mixing XTX and the Crossfire XT would not make sense as the XTX would drop down in speed to balance the XT performance. So if you want to go for Crossfire now or in the future then just stick with the X1900 XT.





http://www.guru3d.com/article/Videocards/315/3/

 

[benjo]

 

[S_D]

Guru3d are wrong.

From ATI's crossfire manual on ATI.com:

"What happens if the CrossFire edition graphics card and the CrossFire Ready graphics card have different clock speeds?

Both cards will continue to operate at their individual clock speeds; neither card is 'stepped down'. The compositing engine on the CrossFire Edition card merges the resulting images independent of the clock speed on either graphics card."

There you go.

Simon.

 

[Jimbo Mahoney]

Guru3d are wrong.

From ATI's crossfire manual on ATI.com:

"What happens if the CrossFire edition graphics card and the CrossFire Ready graphics card have different clock speeds?

Both cards will continue to operate at their individual clock speeds; neither card is 'stepped down'. The compositing engine on the CrossFire Edition card merges the resulting images independent of the clock speed on either graphics card."

There you go.

Simon.

But then the XT won't be able to keep up with the XTX, so you may as well have 2 x XTs anyway...

 

[D.P.]

But then the XT won't be able to keep up with the XTX, so you may as well have 2 x XTs anyway...

Exactly, the XT-X may snot slow down but it wont make any difference to the speed of the rendering as the composition chip[ will still have to wait for the slower card.

 

[LoadsaMoney]

May only be if the mastercard is the faster one, like the x1800, as for x1800 XL Crossfire you had to use the XT master as there was no XL master, and on there they would both run at their normal clock speeds, all you would lose is 256mb from the XT master, so you would have a 256mb XT, and an XL in Crossfire, but seen as its the other way around with the x1900, where the XT is the master, and the slave card is the faster one, then i don't know.

I can't really see it being a problem as the XT is not that much slower than the XTX, can easily be clocked to the XTX speeds as the clocks are not that much higher.