Sable CPU Module Specification

CHAPTER 2
CPU MODULE VARIATIONS
This specification describes CPU modules that are based on the DECchip 21064 and
DECchip 21064-A275 CPU chips. The module differ with respect to on-chip cache
size, backup cache size, operational speed, number of system CPU’s supported and
form factor. This chapter attempts to define the physical and functional design differences
between the Alpha-based processor modules. Table 1 lists the different CPU
modules.
Table 1: CPU Modules Variations
Option
Number
CPU/ I/D cache
Chip-Size Frequency
Cycle
Time
Bcache
Size
Cache
Access
B2020-AA DECchip 21064 8K/8K 190 MHZ 5.26 ns 1 MByte 26.3 ns 4
B2024-AA DECchip 21064-A275 16K/16K 275 MHZ 3.64 ns 4 MByte 25.45 ns 4
2.1 Form Factors
CPUs
Supported
The processor modules measure approximately 340.6 mm x 228.6 mm and use hidensity
connectors. The Figure 4. form factor for the CPU module is shown in
CPU Module Variations 7