Intel STL2 - Manual (Page 14)

STL2 Server Board Architecture Overview STL2 Server Board TPS
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2.1.2 Dual Processor Operation
The Pentium III processor interface is designed to be MP-ready. Each processor contains a
local APIC section for interrupt handling. When two processors are installed, both processors
must be of identical revision, core voltage, and bus/core speeds.
2.1.3 PGA370 Socket
The STL2 server board provides two PGA370 sockets. These are 370-pin zero-insertion force
(ZIF) sockets that a flip chip pin grid array (FC-PGA) package technology processor plugs into.
2.1.4 Processor Bus Termination / Regulation / Power
The termination circuitry required by the Intel Pentium III processor bus (AGTL+) signaling
environment, and the circuitry to set the AGTL+ reference voltage, are implemented directly on
the processor. The STL2 server board provides VRM 8.4 compliant DC-to-DC converters to
provide processor power (VCCP) at each PGA370 socket. The server board provides an
embedded VRM for the primary processor and a VRM socket for the secondary processor.
These are powered from the +5V supply.
2.1.5 Termination Package
If a processor is not installed in a PGA370 socket, a termination package must be installed in
the vacant socket to ensure reliable termination.
2.1.6 APIC Bus
Interrupt notification and generation for the processors is done using an independent path
between local APICs in each processor and the I/O APIC located in the IB6566 South Bridge
component.
2.1.7 Boxed Processors
The Intel Pentium III processor for the PGA370 socket is offered as an Intel boxed processor.
Intel boxed processors are intended for system integrators who build systems from a server
board and standard components.
2.1.7.1 Boxed Process Fan Heatsinks
The boxed Pentium III processor for the PGA370 socket will be supplied with an unattached
fan heatsink that has an integrated clip. Clearance is required around the fan heatsink to
ensure unimpeded airflow for proper cooling. Note that the airflow of the fan heatsink is into
the center and out of the sides of the fan heatsink. The boxed processor thermal solution must
be installed by a system integrator to secure the thermal cooling solution to the processor after
it is installed in the 370-pin ZIF socket.
The boxed processor’s fan heatsink requires a +12V power supply. A fan power cable is
attached to the fan and connects to processor fan headers on the STL2 server board.