I was looking at the ASRock 970 Extreme4's specs lately and found them very confusing.
It supports dual/tri/quad Crossfire and dual SLI but when it comes to the whole PCIe x16/x8/x4 stuff it gets weird.
It says this:
- 3 x PCI Express 2.0 x16 slots (PCIE2/PCIE4: single at x16 (PCIE2) / x8 (PCIE4), or dual at x8 (PCIE2) / x8 (PCIE4) ; PCIE5: x4 mode)
Can someone translate what this means. In dual crossfire is it 2 x x16 or 2x x8 or x16 and x4?
Only first slot works at full speed. Other slots are x16 slots but work at lower speed. 2nd slot is x8 and the third is x4. If use crossfire or sli or just stick in two PCIE x16 cards in first ad slot, then both the cards will work at x8 speed. Here first and second slot share the bandwidth. In a simpler way if you are planning to use two powerful GPU cards then your cards will be bottlenecked.
We'll they don't differ by much but we don't really know if they are using any mods at all. Anway I don't think you'll have much problem adding 2 cards to your system. If you are using 2 cards the memory will be shared anyway so about half the load.