The nForce4 is a motherboard chipset released by Nvidia in October 2004. The chipset supports AMD 64-bit processors (Socket 939, Socket AM2 and Socket 754) and Intel Pentium 4 LGA 775 processors. Models nForce4/nForce4-4x nForce4 is the second evolution of the Media Communications Processor (MCP) and incorporates both Northbridge and Southbridge on a single die (the first was nForce3). The Socket 754 version of the board has the HyperTransport link clocked to 800 MHz (6.4 GB/s transfer rate). Motherboards based on early revisions are mostly referred to as "nForce4-4x" (relating with their ability to handle HT speeds of 4x). Support for up to 20 PCI Express (PCIe) lanes (up to 38-40 lanes for the nForce4 SLI x16). Reference boards are set up with one x16 slot and three x1 slots, leaving 1 lane unused. Support for up to 10 USB 2.0 ports. Support for 4 SATA and 4 PATA drives, which can be linked together in any combination of SATA and PATA to form a RAID 0, 1, or 0+1. Nvidia RAID Morphing, which allows conversion from one RAID type to another on the fly. Nvidia nTune, a tool for easy overclocking and timing configurations. Full 1000 MHz speed on HyperTransport (8 GB/s transfer rate). Eight-channel AC'97 audio. Onboard Gigabit Ethernet. Nvidia ActiveArmor, an onboard firewall solution. (Not available on regular nForce 4) Does not support Windows 98 or Windows Me. nForce4 Ultra The Ultra version contains all of the features of the nForce4-4x version with the addition of: Hardware processing for the ActiveArmor to reduce CPU load. Serial ATA 3 Gbit/s interface with 300 MB/s transfer speeds for SATA 3 Gbit/s drives. Enthusiasts discovered early after the release of nForce4 Ultra that the chipset was identical to nForce4 SLI other than a single resistor on the chip package itself. By modifying this resistor as the SLI is configured, an Ultra can be turned into an SLI. nForce4 SLI The SLI version has all the features of the Ultra version, in addition to SLI (Scalable Link Interface). This interface allows two video cards to be connected to produce a single output. This can theoretically double framerates by splitting work between the two GPUs. On a standard (non x16) nForce4 SLI motherboard, the system can be configured to provide an x16 slot for one graphics board or twin x8 slots for the SLI configuration. A jumper bank must be altered to