- Chapter 3: Microprocessor Types and Specifications
- Pre-PC Microprocessor History
- Processor Specifications
- SMM (Power Management)
- Superscalar Execution
- MMX Technology
- SSE (Streaming SIMD Extensions)
- 3DNow and Enhanced 3DNow
- Dynamic Execution
- Dual Independent Bus (DIB) Architecture
- Processor Manufacturing
- PGA Chip Packagingx
- Single Edge Contact (SEC) and Single Edge Processor (SEP) Packaging
- Processor Sockets and Slots
- Zero Insertion Force (ZIF) Sockets
- Processor Slots
- CPU Operating Voltages
- Heat and Cooling Problems
- Math Coprocessors (Floating-Point Units)
- Processor Bugs
- Processor Update Feature
- Processor Codenames
- Intel-Compatible Processors (AMD and Cyrix)
- P1 (086) First-Generation Processors
- P2 (286) Second-Generation Processors
- P3 (386) Third-Generation Processors
- P4 (486) Fourth-Generation Processors
- P5 (586) Fifth-Generation Processors
- Pseudo Fifth-Generation Processors
- Intel P6 (686) Sixth-Generation Processors
- Other Sixth-Generation Processors
- Itanium (P7/Merced) Seventh-Generation Processors
- Processor Upgrades
- Processor Troubleshooting Techniques
Zero Insertion Force (ZIF) Sockets
When the Socket 1 specification was created, manufacturers realized that if users were going to upgrade processors, they had to make the process easier. The socket manufacturers found that it typically takes 100 pounds of insertion force to install a chip in a standard 169-pin screw Socket 1 motherboard. With this much force involved, you easily could damage either the chip or socket during removal or reinstallation. Because of this, some motherboard manufacturers began using Low Insertion Force (LIF) sockets, which typically required only 60 pounds of insertion force for a 169-pin chip. With the LIF or standard socket, I usually advise removing the motherboardthat way you can support the board from behind when you insert the chip. Pressing down on the motherboard with 60100 pounds of force can crack the board if it is not supported properly. A special tool is also required to remove a chip from one of these sockets. As you can imagine, even the low insertion force was relative, and a better solution was needed if the average person was going to ever replace his CPU.
Manufacturers began inserting special Zero Insertion Force (ZIF) sockets in their later Socket 1 motherboard designs. Since then, virtually all processor sockets have been of the ZIF design. Note, however, that a given Socket X specification has nothing to do with whether it is ZIF, LIF, or standard; the socket specification covers only the pin arrangement. These days, nearly all motherboard manufacturers are using ZIF sockets. These sockets almost eliminate the risk involved in upgrading because no insertion force is necessary to install the chip. Most ZIF sockets are handle-actuated; you lift the handle, drop the chip into the socket, and then close the handle. This design makes replacing the original processor with the upgrade processor an easy task.
Because of the number of pins involved, virtually all CPU sockets from Socket 2 through the present are implemented in ZIF form. This means that since the 486 era, removing the CPU from most motherboards does not require any tools.