Towers, racks, and high-speed link 295Draft Document for Review October 18, 2004 5486Towr.fmare described in IBM Eserver iSeries Migration: System Migration andUpgrades at V5R1 and V5R2, SG24-6055..HSL OptiConnectIn system complexes that contain only V5R1 HSL hardware, the HSLOptiConnect loop implementation consists of loops that may contain up to fourPCI/PCI-X I/O towers and units or external xSeries servers between two iSeriesservers. The same is also true for V5R2 scenarios. However, V5R2 allows forthree iSeries servers to be connected on an HSL OptiConnect loop. When thereare three iSeries servers on a loop, there cannot be any I/O towers or externalxSeries servers on that loop.In an HSL OptiConnect loop, external xSeries servers count against the per looptower limits. Depending on the number of towers and the number of I/Ooperations performed in these towers, overall system performance may beimpacted.HSL copperThe IBM Eserver i5 models have HSL-2/RIO-G ports to serve loops at amaximum speed of 2 GB per second. Only a limited number of towers can beenabled for this higher speed.New ServerModelCopper HSL Cables3, 6 and 15 meterHSL LoopSwitchableTower (IASP)PCI ExpansionTowerxSeries foriSeriesNew ServerModel
