Ready as mine, PCIe 3.0 may be needed for CFX configurations. But unless there is Test proving such, I would not care. (waiting for one myself - test and card of my own)
Why would they limit users to pcie 3.0? That would be a terrible mistake. And if you're talking about performance, we already know from preliminary results that they will be similar to 780 performance, cards that get a 10% boost from pcie 3.0 but that does not mean it "needs" it.
You know the new cards will run crossfire without the bridge, using pcie lanes instead, hence why pcie 3.0 might be needed.
It doesn't mean they will either. While I find it highly unlikely they wont run in 2.0 slots, I'd be inclined to err on the side of caution for the sake of waiting a couple of weeks for reviews.
I'm not entirely sure about that tbh. We know next to nothing about this new bridgeless crossfire, I'd say there's a small chance it might require 3.0. I'd not be willing to fork out $800 + on cards without being 100% sure about it personally.
PCI-E Standards stipulate 3.0 must be backward compatible with previous generations. Btw this is nothing new, bridges have never been essential - only reason they exist is to provide extra bandwidth
Actually to use those bridges part of GPU needs to be designed to allow it. Therefore removal of this and depending on primary existing connection via PCIe saves transistors.
We can be sure, because AMD's own chipsets don't support PCIe 3.0.... Why would AMD develop cards that don't comply with the PCIe standards....and that won't work with their own chipsets? PCIe 3.0 spec stipulates that backwards compatibility with previous PCI Express revisions is required.... Developing a card that requires PCIe 3.0 would be suicide for AMD. None of their current chipsets supports PCIe 3.0... Oh yeah, and there is that part of the PCIe standard that Pill pointed out....
As I said, I find it highly unlikely that it wont support 2.0. I still wouldn't put down better part of a grand until I knew for certain whether it worked or suffered a large performance hit.
It's quite possible there will be some performance penalty....but to be compliant with the PCI Express specifications, all cards are required to be backwards compatible with all previous PCI Express revisions....which means they simply have to work.
So you reckon two R9 290x's will work in crossfire in board only supporting PCI-E 2.0 even though they won't have CF bridge to communicate via, as it's all done through PCI-E slot now
One R9-290X will be enough, pcie3.0, depends if you play at high resolution 2160p or multi monitor setup then yeah you could see pcie2.0 bottleneck, especially in crossfire. And OC that 2600K if not already
