HyperTransport And StreamThru
The fact that NVIDIA uses a technology that originates from AMD shows you just how closely the two companies are cooperating: NVIDIA uses HyperTransport as the link between the Northbridge and the Southbridge. With up to 800 MB/s, HyperTransport far surpasses the bandwidth of all other technologies. A few years ago, both units of the chipset were connected via the PCI bus (e.g., on the 440BX with 133 MB/s). Today, Intel uses its own hub architecture, and it's a similar situation with VIA and SiS (V-Link and MuLTIOL, with 533 MB/s).
In practice, these links should be enough, but HyperTransport has the added advantage of being able to work isochronously - NVIDIA calls this feature "StreamThru." This means that data transfer can happen in real time (iso = equal, chronos = time), where the access for an uninterrupted datastream is guaranteed by the chipset (per Single-Step Arbiter of the nForce2). This is particularly important for applications that rely on constant datastreaming (e.g., CD recording, video editing, hard disk recording).
Luckily, the multifaceted functionality, as well as the better performance, don't require enormous technological effort - the link between Northbridge and Southbridge is created with relatively few circuits (only 8-bit bus width), thereby helping motherboard manufacturers to keep costs down.
External Connection: USB 2.0
A total of six ports are available for the MCP as well as the MCP-T. The MCP chip of the nForce chipset only supported USB 1.1, while the Southbridge of the nForce2 also supports USB 2.0. With a maximum bandwidth of 480 MBit/s, the USB connection is no longer meant for scanners, printers and digital cameras exclusively, but, because of its high data rate and its ability to quickly transfer large amounts of data, it can also be used for external storage systems such as CD recorders and hard disks.
External Connection: IEEE1394 / Firewire
If you want FireWire, you need the nForce2 with the MCP-T unit. This gives you an integrated FireWire controller with up to 400 MBit/s. Nowadays, FireWire is the most important interface for the video segment. Good digital camcorders always feature this interface because when compared to USB, it offers the invaluable advantage of working isochronously, just like the HyperTransport bus between the Northbridge and Southbridge of NVIDIA's StreamThru architecture. All in all, nForce2 seems the ideal candidate for video editing, because apart from the external FireWire connection and the internal data transfer via HyperTransport, its dual DDR with DASP (Dynamic Adaptive Speculative Pre-Processor) also offers a good basis for continuous datastreams.
