While the Nvidia 680i SLI is the enthusiast level chipset from Nvidia, it is certainly not within everybody's price range. 680i LT has brought the price down quite a bit, but there is still a price premium for this high-end chipset, this is why you need to have a mid-range portfolio.
Nvidia has listened, traditionally there are only one or two chipsets for each platform from Nvidia, but currently the company has four for the Core 2 platform, five if you want to count the old 590 Intel Edition. Within the 600-series there are now a total of four options; 680i SLI for the enthusiast, 680i LT for the high-end, 650i SLI for the mid-range and the 650i ultra for the vale end of the market.
We have tested a motherboard from ECS, our first 650i SLI chipset, which we found to be a very good contender. Its performance was on the money, in fact it was not that far behind the 680i-series, only the SLI implementation and a few additional features are where the chipset really differs. 650i falls back on the old twin PCI Express x8 slots for its SLI setup. If you want to use SLI, your graphics cards only run at x8 speeds, this eliminates the ability to run quad-SLI.
Today we have MSI's incarnation of the 650i SLI chipset, the P6N SLI Platinum.