Physical Aspects of the Processor

September 6 (Day); September 5 (Night)

  • Processor Packages:
  • The CPU package is another name for the form factor of the processor: its shape, size, and external features (p. 33).
  • Reasons for Different Packages (p. 33):
  • As CPUs became faster and smarter, they used more pins to link them to the motherboard.
  • As CPUs became faster and smarter, they tend to run hotter than older, less sophisticated CPUs.
  • The Pin Grid Array (PGA) is a square package and has a large number of pins extending from its bottom (p. 34).

An example of a PGA processor.

  • A Single Edge Cartridge (SEC) is contained in a cartridge that snapped into a special slot on the motherboard. It is rarely seen outside the Pentium II (p. 33).

An example of an SEC processor.

  • Motherboard Compatibility:
  • A slot or socket is the physical connection used to connect a processor to the motherboard. The processor slot or socket on the motherboard must match the slot or socket required by your processor.
  • A socket is the older connection. It is usually a square-shaped connection where the processor lies flat into the motherboard.
  • Typically, processors with a PGA form factor plug into sockets.
  • Slots were developed to accept cartridges. Slots are rectangular.
  • Typically, processors with an SEC form factor plug into a slot.
  • The typical motherboard supports a very limited number of CPUs. It often depends on complex issues such as the socket or slot type or CPU speed (p. 38).
  • Motherboards come with motherboard books that describe in great detail all of the technical aspects of the motherboard. Here is the best place to look for motherboard compatibility (p. 39).
  • Many makes and models of CPUs come in two or more socket types, so that you cannot rely on entirely on the make and model of a CPU to determine whether your motherboard supports it (p. 39):
  • Pentium 4 processors, for example, come in two varieties: Socket 423 and Socket 478 (p. 39).
  • Sockets and Slots:
  • Socket 7 – 321 pins; used Pentium class chips, from 75MHz on up, MMX processors, the AMD K5, K6, K6-2, K6-3, 6x86, M2 and M3, and Pentium MMX Overdrives.

Socket 7

  • Slot 1 – 242 pins; rectangular; used in all Pentium 2; used by older Pentium 3 and Celeron.
  • Slot A – used by AMD Athlon
  • Socket 370 – 370 pins; used by newer Pentium 3’s.

Socket 370 (left); Slot 1 (right)

  • Socket 423 – 423 pins; used by older Pentium 4 (from 1.3 - 2 GHz)
  • Socket 478 – 478 pins; used by newer Pentium 4 (from 1.6 – 3.4 GHz)
  • Pentium Makes and Models:

Classic Pentium

Introduced: / March 1993
Processor Speeds: / 60-200 MHz
Memory Bus Used: / 66 MHz
Maximum Memory: / 4 GB
L1 Cache: / 16 KB
L2 Cache: / None
First processor to use a 64-bit data bus.
/

Pentium 2

Introduced: / May 1997
Processor Speeds: / 233-450 MHz
Memory Bus Used: / 66,100 MHz
Maximum Memory: / 64 GB
L1 Cache: / 32 KB
L2 Cache: / 512 KB
First processor to use 512 KB L2 Cache.

Pentium 3

Introduced: / Feb. 1999
Processor Speeds: / 400 MHz – 1 GHz
Memory Bus Used: / 100, 133 MHz
Maximum Memory: / 64 GB
L1 Cache: / 32 KB
L2 Cache: / 512 KB
Use of SSE (Streaming SIMD Extensions) for multimedia applications.
/

Pentium 4

Introduced: / Sometime in 2000
Processor Speeds: / 1.2 GHz – 3 GHz
Memory Bus Used: / 400, 533, 800 MHz
Maximum Memory: / 64 GB
L1 Cache: / 20 KB
L2 Cache: / 512 KB
Initially unstable, redesigned in 2001.
  • Processor Cooling:
  • CPUs run too hot for their packaging and need external cooling (p. 47).
  • The temperature of the processor must be kept below the Intel maximum temperature of 185 degrees Fahrenheit. Using a heat sink and a fan can lower this temperature to 90-110 degrees Fahrenheit.
  • A heat sink sits on top of the CPU and draws heat from the processor so that the fan may dissipate it (p. 47).
  • Between the heat sink and the processor, you should apply thermal compound. Thermal compound prevents heat from escaping the area between the processor and heat sink (p. 48).
  • The purpose of fans is to draw air from the processor and the heat sink (p. 48).
  • Fans are judged according to size, airflow, and noise (p. 48).
  • Thermal compound is grease or crème placed between the processor and the heat sink or fan; used to eliminate air gaps and prevent heat from escaping before it reaches the heat sink or is cooled by the fan.

Thermal Compound