Expreview has gotten its hands on a reference nForce 780i board from Nvidia and they've put it through its paces. We've written about the differences between this and the 680i board in the past, but there are a few interesting things that weren't revealed at that time.
First of all, the 780i is only an interim solution until Nvidia launches the C73 next year. This new chipset will add support for DDR3 and 1,600MHz FSB, while the C72 or the 680i/780i is limited to 1,333MHz FSB and DDR2 memory.
But back to the 780i, which is as we told you, is not a new chipset and it's actually detected as the 680i by CPU-Z. The addition of the NF200 chipset adds two x16 PCIe 2.0 slots and 32 PCI Express lanes. The old 680i SPP provides a further two PCIe x1 lanes, while the MCP adds a further x16 PCIe slot, the possibility of a x8 slot and support for four x1 slots or devices.
This means that you can only use two PCIe 2.0 cards with the 780i chipset, at least in terms of power draw and extra performance that you might get from the new interface.
The benchmark numbers are less than thrilling and the 780i chipset is at least not a performance leader at this stage, but some further tuning from Nvidia's side or possibly the board partners might change this.
We'd recommend that you wait for the C73, especially if you already own a 680i based board.
You can find the full review in Chinese here, although the conclusion and all the graphs are in English