IBM System z10 I/O subsystem

The cache and memory subsystems of the IBM POWER8 processor

“…Starting with the POWER4 processor [12] and z10* [13] processors, the IBM I/O subsystem was built upon a proprietary ecosystem of I/O chips [14] attached to IBM's proprietary GX bus and later GX+ and GX++ buses to achieve higher I/O throughput than possible with the standardized interfaces available at the time. Different break-out I/O hub chips provided connectivity to PCI-X**, PCIe devices, and InfiniBand** or Ethernet fabrics.…”

Overview of IBM zEnterprise 196 I/O subsystem with focus on new PCI Express infrastructure

“…System z started its migration from proprietary I/O expansion links to industry-standard links in z10 with the introduction of internal InfiniBand links [1]. With the introduction of zEnterprise 196, a significantly larger step has been taken into high-volume industry-standard I/O links by migrating to PCIe.…”

“…Each book has up to eight slots for I/O fan-out cards, and several different cards are available. The host channel adapter-2 copper (HCA2-C) fan-out card supports the traditional I/O cage over the InfiniBand** load/store (IBLS) protocol [1]. In addition, the fan-out card connection to the processor book is the I/O hub controller (i.e., GX) bus, the same I/O interface used in System z10* (z10*).…”