Base 3

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Base 3
Socket 3.jpg
design type PGA - ZIF
contacts 237 (19 × 19)
Bus protocol 486
Bus cycle 25, 33, 40, 50 MHz
Operating voltage 3.3V, 3.45V, 5.0V
Processors Intel i486SX (16–33 MHz)
Intel i486SX2 (50–66 MHz)
Intel i486DX (20–33 MHz)
Intel i486DX2 (50–80 MHz)
Intel i486DX4 (75–120 MHz)
Intel Pentium OverDrive (63–83 MHz)
AMD Am486 DX-2 (80 MHz)
AMD Am5x86 (133 MHz)
Cyrix 5x86 (100–120 MHz)
and compatibles

The base 3 was the standard socket for the Intel i486 processor. In contrast to the predecessor socket 2 , processors for socket 3 could be supplied with 5.0 V, 3.3 V or 3.45 V processor core voltage (V core ) depending on the type . A second socket 3 was often provided on mainboards in order to retrofit a math coprocessor , the Intel 80487 , which was missing in the SX variants of the i486. The 80487 was actually an i486 DX with a different pin assignment, the i486SX processor was completely switched off.

Typical chipsets for socket 3 mainboards were: