10 pSeries 610 Models 6C1 and 6E1 Technical Overview and Introduction
2.1 Processor and cache
The IBM® ^ ™ pSeries™ 610 Models 6C1 and 6E1 have two processor card slots
and can accommodate three different processor cards, a 1-way 333 MHz, a 1-way 375 MHz,
or a 1-way 450 MHz. Note that slot 1 must have a processor card installed for normal
operation.
If your system unit uses two processor cards, both processor cards must be of the same
clock speed.

2.1.1 L1 and L2 cache

Models 6C1 and 6E1 use a 64 KB data and a 32 KB instruction 128-way set associative L1
cache. The size of both data and instruction cache reduces the number of cache misses,
results in more cache hits, and maximizes performance. Both data and instruction cache are
parity protected.
The L1 cache is effectively supplemented by a 4 MB 4-way set associative L2 cache, which is
located on the 333 MHz and 375 MHz processor cards (8 MB for the 450 MHz processor
card). The speed of the L2 cache is dependent upon the processor speed. The POWER3-II
uses a private 32-byte L2 cache bus, operated at 166.5 MHz with the 333 MHz processor (1:2
ratio) 250 MHz with the 375 MHz processor card (2:3 ratio), and 225 MHz with the 450 MHz
processor card (1:2 ratio). Both the enhanced clock speed and 4-way set associative L2
cache improve cache efficiency. The L2 controller uses a least recently used (LRU) algorithm
to avoid replacing recently used cache data and a set pred iction mechanism that helps
reduce L2 cache misses.
The L2 cache uses a direct mapped cache methodology. There is a dedicated external
interface to the L2 cache not shared with the 6XX bus. This allows concurrent access to both
the L2 cache and the 6XX bus.

2.1.2 POWER3-II architecture

The POWER3-II processor offers technical leadership for floating point applications and
high-performance numeric intensive computing (NIC) workstations by integrating two
floating-point, three fixed-point, and two load/store execution units in a single 64-bit POWER3
implementation. Table2-1 lists some of the technical features of the POWER3-II processors.
Table 2-1 Technical features of POWER3-II
Note: Installing a processor card into your system unit may require updating the fir mware.
A diskette or CD-ROM is included with your new processor card if that is required. Check
also the following Web page for the latest available firmware:
http://www.rs6000.ibm.com/support/micro/
Description POWER3-II
Chip Die Size 163 mm2
Transistors 23 million
Power Avg/Max 23W/31W@333 MHz,
26W/33W@375 MHz,
31W/42W@450 MHz
CMOS Technology 7S, 6 layers metal, copper interconnect
Lithography 0.22 µm