hyper transport (HT)
HyperTransport is a high-speed connection developed by Advanced Micro Devices (AMD) and API Networks for fast data transfer in personalcomputers. HyperTransport is specifically designed for communication between the different devices on a board or motherboard; for example, the Athlon uses this I/O bus to exchange data with other central processing units( CPU) and the northbridge.
The first version of HyperTransport worked with a clock rate of 800 MHz and achieved data transfer rates of 6.4 GB/s in the 16 bit version. Version 2.0 with a clock frequency of 1.4 GHz achieves data rates of 22.4 GB/s, with a 32-bit bus width. The combined bandwidth of 22.4 GB/s is roughly 100 times the PCI bus that HyperTransfer is compatible with, as well as PCI-X and PCI-Express.
Bus widths can vary between 2 and 32 bits, as can clock speeds between 200 MHz and 1.4 GHz, allowing optimization between cost and efficiency. Alternatives for high-speed point-to-point connections on boards are Quick Path Interconnect( QPI) and Ultrapath Interconnect (UPI). HyperTransport uses multiple links to connect processors to the Accelerated Graphics Port( AGP), PCI bus or PC interfaces.
The specifications of HyperTransfer are defined and published by the HyperTransport Consortium. This organization is a non-profit organization that drives development and manages the specification documents.
Alternatives for fast point-to-point connections on boards are Quick Path Interconnect (QPI) and Ultrapath Interconnect (UPI).