Hardware Reference
In-Depth Information
bycompanyinternalnetworksandapplications. Youcanusetheprocessorserialnum-
ber in applications that benefit from stronger forms of system and user identification,
such as the following:
•
Applications using security capabilities
—Managed access to new Internet con-
tent and services; electronic document exchange.
•
Manageability applications
—Asset management; remote system load and config-
uration.
Although the initial release of Pentium III processors was made in the improved SECC2
packaging, Intel later switched to the FC-PGA package, which is even less expensive to
produce and enables a more direct attachment of the heatsink to the processor core for
better cooling. The FC-PGA version plugs into Socket 370 but can be used in Slot 1 with
a slotket adapter.
All Pentium IIIprocessors have either 512KB or256KB ofL2cache, which runsat either
half-core or full-core speed. Pentium III Xeon versions have 512KB, 1MB, or 2MB of L2
cache that runs at full-core speed. The Pentium III Xeon is a more expensive version of
the Pentium III designed for servers and workstations. All PIII processor L2 caches can
cache up to 4GB of addressable memory space and include ECC capability.
Celeron
The Celeron processor is a chameleon, more of a marketing name than the name of an
actual chip. In its first two versions it was originally a P6 with the same processor core as
thePentium II;later itcame withthesame coreasthePIII,thentheP4,while morerecent
versions use the same core as the Core 2 processors. The Celeron name represents essen-
tially a version of Intel's current mainstream chip that Intel has repackaged for lower-cost
PCs.
Increating the original Celerons, Intel figured that bytaking aPentium IIanddeleting the
separateL2cachechipsmountedinsidetheprocessorcartridge(anddeletingthecosmetic
cover), it could create a “new” processor that was basically just a slower version of the
Pentium II. As such, the first 266MHz and 300MHz Celeron models didn't include L2
cache. Unfortunately, this proved to have far too great a crippling effect on performance,
so starting with the 300A versions, the Celeron received 128KB of on-die full-speed L2
cache, which was actually faster and more advanced than the 512KB of half-speed cache
used in the Pentium II it was based on at the time! In fact, the Celeron was the first PC
processor to receive on-die L2 cache. It wasn't until the Coppermine version of the Penti-
um III appeared that on-die L2 cache migrated to Intel's main processors.
