Interconnect Architectures

Concepts

Network On A Chip System Bus

General

AGP CAPI CCIX CCPI DMI (IBM) DMI (Intel) EISA Gen-Z Hydra HT IF ISA LIPINCON Micro Channel Multibus NVLink PCI PCIe PXI Q-Bus QPI S-100 SS-50 Unibus UPI VLB

Peripheral

1-Wire ACCESS.bus Centronics GPIB MIDI RS-232 RS-422 RS-423 UNI/O bus

Storage Devices

NVMe PATA SATA SATAe SSA SCSI

Audio Devices

I²S S/PDIF

Hydra or Hydra Interface is a custom interface designed by HiSilicon for their Kunpeng (Hi16xx) family of ARM server processors designed to facilitate coherent symmetric multiprocessing support.

Overview

The Hydra Interface is a high-speed cache coherent interconnect architecture designed to facilitate symmetric multiprocessing between their Kunpeng processors. The Hydra interface is multiplexed over a number of extra PCIe lanes. Each Hydra interface has either x4 or 8x lanes.

When in 2-way SMP, multiple Hydra interfaces are combined.

2-way SMP Hydra Interface
Links		10 GT/s	12 GT/s
1	1x8	10 GB/s	12 GB/s
2	2x8	20 GB/s	24 GB/s
3	3x8	30 GB/s	36 GB/s

In a 4-way SMP, three Hydra interfaces are used per CPU with one link between each CPU, creating an all-to-all connection.