The new NVIDIA nForce 650i SLI and 680i SLI are Intel Core 2 compatible and replace the nForce 570 SLI and 590 SLI Intel Editions. NVIDIA’s new nForce 650i SLI and 680i SLI aren’t exactly new per say but rather a re-branding of the previously released nForce 570 SLI and 590 SLI Intel Editions. The new nForce 650i SLI SPP pairs with an nForce 430 SLI MCP to provide a total of 29 PCI Express lanes. In SLI mode the nForce 650i SLI delivers two half-speed PCI Express x16 slots.
NVIDIA’s nForce 680i SLI is essentially a revised nForce 590 SLI Intel Edition. Manufacturers were reluctant to adopt the C51 nForce 590 SLI Intel Edition due to front-side bus scaling issues. Nevertheless the C55 nForce 680i SLI is paired with the nForce 590 SLI MCP a total of 48 PCI Express lanes. As with the nForce 590 SLI Intel Edition, the nForce 680i SLI supports two full-speed PCI Express x16 slots.
Other supported features of the nForce 650i SLI and 680i SLI include 3.0Gbps SATA, Gigabit Ethernet, ATA-133, USB 2.0, high definition audio and support for five PCI slots are supported by both chipsets. While the nForce 650i SLI and 680i SLI are new model numbers, the chipsets are essentially identical to the nForce 570 SLI and 590 SLI Intel Editions which was only adopted by OEM system manufacturers and Asus.
The chipset dosent go above like 350 FSB. Some news on VR-Zone claimed that the new chip went as far as 500 Mhz. (and the RD600 went some 20 mhz faster