IBM eserver i5 Handbook page 328

5486Towr.fm
Copper HSL cables have a higher bandwidth compared to the optical HSL
cables. The optical cables are available in longer lengths (up to 250m compared
to 15m for copper). Optical HSL cables are smaller and easier to work with,
particularly during installation.
The longer optical cable lengths extend the distance between I/O units and the
Model 550, 570, 595, 825, 830, 840, 870, and 890 servers from the current 15m
to 250m. Expanded I/O location alternatives can help improve data reliability and
protection.
The HSL bus structure provides:
Performance improvements and future system growth
– Up to 1 GB/sec technology with HSL or HSL-2 (copper HSL or HSL-2
cables)
– Up to 2 GB/sec technology with HSL-2/RIO-G (copper HSL-2 cables) on
Models 520, 550, 570, and 595 up to the10m cable length: Use of the 15m
cables on these loops results in reduced speeds.
Simplified implementation
– Loop technology for redundancy
– Multiple towers per loop
– 1.75m, 3m, 6m, 15m copper HSL cables
– 6m, 30m, 100m 250m optical HSL cables
– 4m,10m, 15m copper HSL-2 cables
– 6m, 10m HSL to HSL-2 cables
– Migration tower attachment supports SPD I/O towers and #5065/#5066
Storage/PCI Expansion Towers
Homogeneous HSL network with HSL adapters
– Simple HSL clusters (two iSeries)
– Complex HSL clusters (three iSeries with V5R2 or later)
– xSeries for iSeries HSL connectivity
– Switchable HSL connected tower with IASP
The following figure shows the HSL connectivity of loops.
Note: Servers and I/O towers can be on the same copper loop, whether the
connection is HSL or HSL-2. The appropriate HSL cabling must be used.
For more information about HSL configuration per model, see the product
sections within this book.
You can find the base rules for tower placement in the IBM Eserver iSeries and
AS/400e System Builder, SG24-2155. HSL rules and migration considerations
IBM Eserver i5 and iSeries System Handbook
294
Draft Document for Review October 18, 2004