Mellanox MetroX devices exist which allow up to 80 kilometer connections. IB active fiber (optical) cables can be up to 300 meters using up to FDR (only 100 meters on FDR10). IB passive copper cables can be up to 7 meters using up to QDR, and 3 meters using FDR. A DDR adapter meant for a PCI Express 8x slot should work in a PCI Express 4x slot (with half the bandwidth). Connections should be established at the lowest common denominator. IB devices are almost always backwards compatible. For comparison 10Gb Ethernet is more like 7.22us, ten times more than FDR's latency. IB's latency is incredibly small: SDR (5us) DDR (2.5us) QDR (1.3us) FDR (0.7us) EDR (0.5us) and HDR (< 0.5us). When using the common 4X link devices, this effectively allows total effective throughputs of: SDR of 8Gb/s DDR of 16Gb/s QDR of 32Gb/s FDR of 54.54Gb/s EDR of 96.97Gb/s and HDR of 193.94Gb/s. IB devices are capable of sending data over multiple links, though commercial products standardized around 4 links per cable. Starting with FDR, IB uses 64/66 encoding, allowing a higher effective throughput to signaling rate ratio of 96.97%: FDR at 13.64Gb/s/link EDR at 24.24Gb/s/lane and HDR at 48.48Gb/s/link. Planned around 2017 will be HDR (High Data Rate) at 50Gb/s.īecause SDR, DDR, and QDR versions use 8/10 encoding (8 bits of data takes 10 bits of signaling), effective throughput for these is lowered to 80%: SDR at 2Gb/s/link DDR at 4Gb/s/link and QDR at 8Gb/s/link. IB is now delivering EDR (Enhanced Data Rate) at 25Gb/s (matching 25Gb Ethernet). It launched using SDR (Single Data Rate) with a signaling rate of 2.5Gb/s per lane (corresponding with PCI Express v1.0), and has added: DDR (Double Data Rate) at 5Gb/s (PCI Express v2.0) QDR (Quad Data Rate) at 10Gb/s (matching the throughput of PCI Express 3.0 with improved coding of PCIe 3.0 instead of the signaling rate) and FDR (Fourteen Data Rate) at 14.0625Gbps (matching 16GFC Fibre Channel). IB transfer rates corresponded in the beginning to the maximum supported by PCI Express (abbreviated PCIe), later on, as PCIe made less progress, the transfer rates corresponded to other I/O technologies and the number of PCIe lanes per port was increased instead. With large businesses benefiting so much from jumping to newer versions, the maximum length limitations of passive IB cabling, the high cost of active IB cabling, and the more technically complex setup than Ethernet, the used IB market is heavily saturated, allowing used IB devices to affordably be used at home or smaller businesses for their internal networks.
ARCH LINUX W DOWN SOFTWARE
IB software is developed under the OpenFabrics Open Source Alliance Affordable used equipment
Facebook, Twitter, eBay, YouTube, and PayPal are examples of IB users. IBM, HP, and Cray are also members of the InfiniBand Steering Committee. IB is most often used by supercomputers, clusters, and data centers. IB hardware is made by Mellanox (which merged with Voltaire, and is heavily backed by Oracle) and Intel (which acquired QLogic's IB division in 2012).
ARCH LINUX W DOWN FREE
This allows the OS's and CPU's to remain free while the high bandwidth transfers take place, which can be a real problem with 10Gb+ Ethernet. IB adapters can handle the networking protocols, unlike Ethernet networking protocols which are ran on the CPU. IB can transfer data directly to and from a storage device on one machine to userspace on another machine, bypassing and avoiding the overhead of a system call. IB provides high bandwidth and low latency. InfiniBand (abbreviated IB) is an alternative to Ethernet and Fibre Channel.
ARCH LINUX W DOWN HOW TO
This page explains how to set up, diagnose, and benchmark InfiniBand networks.
0 kommentar(er)
