IBM 88553RX, Installation Manual

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54
IBM
Eserver
xSeries 455 Planning and Installation Guide
The Itanium 2 processor cache subsystem has three levels, all of which are
on-die cache. In addition to this, IBM provide a fourth level of cache to
manage the data and logic between the processors.
The increased physical memory includes the following benefits for
applications:
– Each application can support more users. For a comparison of the number
of maximum connected users in SAP for various hardware platforms
(including Itanium 2), visit the following link:
http://www.sap.com/benchmark/
– Each application has better performance and more applications can run
simultaneously and remain completely resident in the system's main
memory. This reduces or eliminates the performance penalty of swapping
pages to and from disk.
– Each application has more memory for data storage and manipulation.
Databases can store more of their data in the physical memory of the
system. Data access is faster because disk reads are not necessary.
– Applications can manipulate large amounts of data easily and more
reliably. Video composition and modeling for scientific and financial
applications benefit greatly from memory-resident data structures that are
not possible on 32-bit operating systems.
For the enterprise customer, a larger physical memory subsystem provides
access to more data more quickly from system memory, since much more
data can be held near the processor for faster calculations and data analysis.
Large memory addressability allows larger file system caches for read-ahead
and write-behind I/O operations, and also allows retention of large amounts of
data in memory instead of repeatedly reading the data from disk. Combined
with high-memory bandwidth and a variety of performance optimization
techniques, this solution provides the performance the enterprise market
needs.