Like what you see? Get it in one document for easy printing!
Click Here!
Use coupon code "SAVE50" to get it half price!

Custom Search







Table Of Contents  CertiGuide to A+ (Core Hardware)
 9  Chapter 0010:  CPUs
      9  V  Pentium Family CPUs

Previous Topic/Section
V  Pentium Family CPUs
Previous Page
Pages in Current Topic/Section
1
Next Page
Pentium MMX
Next Topic/Section

Pentium Classic

The original Pentium was out (introduced) at 60MHz, and was later upped to 66Mhz. While the Pentium rocked the digital world, it did have one challenge. Operating at five volts, the CPU put out tremendous heat, limiting the ability to create even faster processors. The 66 MHz Pentium consumed a whopping 16 W of power (3.2 Amps). This made laptop computers fry legs of the laps they sat on. The solution was simple, as soon as it was technically feasible. Lower the required voltage. And lowering the voltage to about 3.3 volts exactly what Intel did, starting with the 75Mhz Pentium. Actually, the 75Mhz Pentium used 3.465 volts, but you get the idea.

Bending Pins

CPUs became more complex by additional pins added to support the increased load. This increased the possibility of bending the contacts on the CPU as it was being inserted into the socket. Insertion force reaching 100 pounds (45 Kilograms) became required. Pushing this hard requires removing the system board from the case.


Intel worked on getting the requirements down, and labeled each Pentium with a suffix:

  • Standard (STD): 3.30V

  • Voltage Reduced (VR): 3.38V

  • VR Extended (VRE): 3.50V

Voltage ‘standards’ begin to get confusing with later Pentiums, all Pentium Overdrive CPUs, and settles to 3.3Volts and 2.8Volts at the core of the CPU through the PII.

Pentium Volts

The majority of Pentium CPUs used 3.3 Volts.


To make sure the newer Pentium using the lower voltage was not inadvertently plugged into a system board using five volts Intel changed the socket type (Socket 4) to a 296-pin arrangement and staggered the pinouts to create the Staggered Pin Grid Array (SPGA).

Another feature of the second-generation offering was the Advanced Programmable Interrupt Controller (APIC) that in concert with a dual-processor interface allowed system board makers to create systems holding multiple CPUs. This really helps out some Operating Systems, such as NT handling larger loads. When multiple-processors are used the process is known as Symmetric Multi-Processing (SMP).

SMP

SMP
(Symmetric Multi-Processing) allows the use of multiple processors sharing a common operating system and memory.


Another issue facing the Intel engineers was the fact that they were able to get CPU speeds moving along faster than the rest of the system bus could handle. The solution was to use a clock-multiplier circuit to run the processor at speeds faster than the rest of the system. Table 10 shows a typical multiplier and system board speed.


Table 10: Pentium Processor Multipliers and Bus Speeds

Processor

Multiplier

Bus Speed

Pentium 75

1.5 x

50Mhz

Pentium 90

1.5 x

60Mhz

Pentium 100

1.5 x

66Mhz

Pentium 120

2.0 x

60Mhz

Pentium 133

2.0 x

66Mhz

Pentium 150

2.5 x

60Mhz


ZIF Socket

To avoid damaging CPUs during installation, the ZIF (Zero Insertion Force) socket was developed.



Previous Topic/Section
V  Pentium Family CPUs
Previous Page
Pages in Current Topic/Section
1
Next Page
Pentium MMX
Next Topic/Section

If you find CertiGuide.com useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider buying an inexpensive PDF equivalent of the CertiGuide to A+ (Core Hardware) from StudyExam4Less.com. (Use coupon code "SAVE50" to save a full 50% off the already low price!) Thanks for your support!
Donate $2
Donate $5
Donate $10
Donate $20
Donate $30
Donate: $



Home - Table Of Contents - Contact Us

CertiGuide to A+ (Core Hardware) (http://www.CertiGuide.com/aplush/) on CertiGuide.com
Version 1.0 - Version Date: December 6, 2004

Adapted with permission from a work created by Tcat Houser.
CertiGuide.com Version Copyright 2004 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.