Crossfire limitations? Not with R520

[Apple740]

"Poke around the web recently and you'll get sniffs of X8-series Crossfire not doing anything over 60Hz at 1600x1200 on analogue outputs, or higher than 1920x1200 at all, because it feeds DVI output from the slave into the compositing engine on the master. That's pretty much correct.

Crossfire with R5-series GPUs suffers no such limitation given the dual-link outputs for DVI. Enough said."

http://www.hexus.net/content/reviews/review.php?dXJsX3Jldmlld19JRD0xNjIyJnVybF9wYWdlPTE=

 

[^eMpTy^]

...I thought the limiting factor was the compositing chip, not the DVI output...being able to output dual-link doesn't make the compositing chip any faster...

 

[Apple740]

Beyond3d goes a little bit deeper:

"One recent discussion that has cropped up is that of a limitation with current Crossfire configurations with a maximum resolution of 1600x1200 at 60Hz, while many concentrated on the output of the Crossfire master card, this limitation actually stems from the capabilities of the source of image from the slave card - with ATI employing the DVI output of the slave card to produce the the digital output of the portion of the image(s) produced from the slave the to provide to the master card the rendering resolution and refresh rates are limited by the DVI output of the current Radeons. X800 and X850 only integrated a single link TMDS transmitter, hence a display limitation of 1600x1200 @ 60Hz; with all of the next generation graphics chips guaranteed to support two dual link TMDS transmitters if the next generation Crossfire uses the same master/slave with compositor system then just using one of the TMDS transmitters should mean the maximum resolution of the slave image could go up to 2048x1536 @ 85Hz and ATI only need include a dual link DVI on the master card and these higher resolutions could be achieved with Crossfire."

http://www.beyond3d.com/previews/ati/avivo/