Specifications

Computer Architecture and Maintenance (G-Scheme-2014)
Notice that although the chip for Socket 2 is called Pentium OverDrive, it is not
a full-scale (64-bit) Pentium. Intel released the design of Socket 2 a little prematurely
and found that the chip ran too hot for many systems. The company solved this
problem by adding a special active heatsink to the Pentium OverDrive processor. This
active heatsink is a combination of a standard heatsink and a built-in electric fan.
Unlike the aftermarket glue-on or clip-on fans for processors that you might have seen,
this one actually draws 5V power directly from the socket to drive the fan. No external
connection to disk drive cables or the power supply is required. The fan/heatsink
assembly clips and plugs directly into the processor and provides for easy replacement
if the fan fails.
Another requirement of the active heatsink is additional clearance—no
obstructions for an area about 1.4" off the base of the existing socket to allow for
heatsink clearance. The Pentium OverDrive upgrade is difficult or impossible in
systems that were not designed with this feature.
Another problem with this particular upgrade is power consumption. The 5V
Pentium OverDrive processor draws up to 2.5 amps at 5V (including the fan) or 12.5
watts, which is more than double the 1.2 amps (6 watts) drawn by the DX2 66
processor.
Socket 3
Because of problems with the original Socket 2 specification and the enormous
heat the 5V version of the Pentium OverDrive processor generates, Intel came up with
an improved design. This processor is the same as the previous Pentium OverDrive
processor, except that it runs on 3.3V and draws a maximum 3.0 amps of 3.3V (9.9
watts) and 0.2 amp of 5V (1 watt) to run the fan—a total of 10.9 watts. This
configuration provides a slight margin over the 5V version of this processor. The fan is
easy to remove from the OverDrive processor for replacement, should it ever fail.
Intel had to create a new socket to support both the DX4 processor, which runs on 3.3V,
and the 3.3V Pentium OverDrive processor. In addition to the 3.3V chips, this new
socket supports the older 5V SX, DX, DX2, and even the 5V
Pentium OverDrive chip. The design, called Socket 3, is the
most flexible upgradeable 486 design. Figure shows the
pinout specification of Socket 3.
Prepared By – Prof. Manoj.kavedia (9860174297 – 9324258878 ) (www.kavediasir.yolasite.com)
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