48
Rapier Series Switch
C613-03020-00 REV K
Compression
PAC-based compression has the following features:
■
Local 32-bit processor for high speed control and data transfer.
■
Dedicated high performance 32-bit compression hardware.
■
High compression ratio Lempel-Ziv algorithm in hardware.
■
2 MBytes of history memory.
■
Support for up to 127 compression channels.
Compression and decompression operations are performed by a 32-bit data
compression coprocessor specifically designed for high-performance Lempel-
Ziv compression applications. The 2 MBytes of history memory allows up to
127 individual data links to use compression concurrently, enabling PACs to
provide compression for complicated network architectures.
Figure 25
shows
typical compression ratios achieved by a PAC for a representative set of file
types.
Figure 25: Typical hardware compression ratios by file type
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1
2
3
4
5
6
7
Font
Program Window
Text
Object Spread
sheet
C source
EPS
Bitmap
TIFF
File Type
Compression Ratio
CMPRATIO
