Hardware Zone took a look at the GA-G1975X Intel 975X Express chipset based motherboard from Gigabyte. Here's a small quote from their full test report:

So with Intel's recent launch of their 975X Express chipset, there is finally some competition, even if it's only on the Intel front. The 975X Express is actually a chipset refresh of their current 955X Express, much like what the NVIDIA nForce4 SLI X16 is to the nForce4 SLI. The only main difference is in the graphics department. The 975X Express supports configurable PCI Express lanes to allow splitting the PCIe x16 link into two PCIe x8 links for a balanced dual graphics setup..



Link: HardwareZone