Despite the unique naming conventions of NVIDIA chipset division, you can clearly see that from a feature stand point not much has changed from the 680i block diagram we saw in 2006.  We are still connected to the Intel CPU with a 1333 MHz front-side bus while the two chips in the 780i communicate via a HyperTransport connection.  The chipset's memory controller is still rated at DDR2-800 MHz memory though with SLI Memory it can automatically overclock as high as 1200 MHz. 

The new addition to the picture is the nForce 200 chip - what is essentially a PCI Express 1.0 to PCI Express 2.0 bridge that allows for two full x16 PCIe 2.0 connections for GPUs.  These PCIe 2.0 connections are then fed back to the north bridge (or 780i SPP) via a standard x16 PCIe 1.0 connection.  This has raised concerns that the PCIe 2.0 on the 780i isn't "true" PCIe 2.0 and we tend to agree.  But in reality, the differences between the two technologies with today's graphics boards are negligible. 

The third PCI Express slot is actually a PCIe 1.0 x16 path sourced from the 780i MCP, or south bridge.  Essentially what we are seeing is an identical picture that the 680i motherboards used to generate three PCIe connections for GPUs but now we have some pseudo-PCIe 2.0 in the mix. 

And...well that's pretty much it.  When we first heard about the 780i SLI chipset, the main new features were PCIe 2.0 support, 3-Way SLI support and ESA support; both 3-Way SLI and ESA were introduced on the 680i chipset before we got our first 780i SLI motherboard sample making the launch less impressive and making us less than enthusiastic about it.

Replacing the "7" with a "6" in the model number would hardly go noticed in my mind as the features on the 780i and 680i motherboards are obviously nearly identical.  The good news is that 780i SLI motherboards will have full support for 45nm Penryn-based processors; something that only the later revisions of the 680i SLI motherboards could claim.