
IT Certification Practice Exams

A+ Essentials Tutorial

2.0 Laptop and Portable Devices

2.1 Identify the fundamental principles of using laptops and portable devices

Identify and distinguish between mobile and desktop motherboards and processors including throttling, power management and WiFi

Laptop Processors:

The main difference between laptop and desktop processors is the clock frequency and the power consumption. Desktop processors are optimized for higher performance at the cost of large heat production and space. On contrast, laptop processors are optimized for smaller energy requirements (in turn improving battery backup time) at the cost of lower clock frequency. Higher performance versions are also available for laptops that consume more power. The disadvantage of using higher performance processors (with large wattage requirements) is large heat production, and smaller battery backup time.

Laptop processors typically use a surface-mount Micro-FCBGA (Flip Chip Ball Grid Array), or slot-mount form factor, while desktop processors use a socket-mount form factor. The main advantage is smaller space requirement. If mounted using FCBGA, the processor replacement requires special tools.

Various types of mobile laptop processors are briefly discussed below:

Intel Core 2 Duo (Merom):

Core Duo is successor to Core Solo offering 5-20% more speed. The Core 2 Duo for laptops is identical to the desktop Cure 2 Duo processors but the notebook-processors work at lower Frontside bus clock (1066 vs 667 MHz). The performance is 20-25% lower than Desktop PCs because of the lower Frontside bus clock and the slower hard disks.

The energy need of the processors is marked by pre-set letters in front of the type designation (number).
E ... 55-75 Watts
T ... 25-55 Watts (standard version in notebooks)
L ... 15-25 Watts (low voltage)
U ... <15 Watts (ultra low voltage)

Intel Core Duo (Yonah)

After first benchmarks the Core Duo completes all tests at least just as fast as a equivalent Pentium M. With applications, which were designed for multi-processors, the performance can be nearly twice as fast as with the Pentium M (e.g. CineBench around 86% fast)

Pentium Dual Core T2060: 1.6 GHz, FSB 533 MHz, 1 MB L2 Cache (the return of the name Pentium, though Yonah core)
Pentium Dual Core T2080: 1.73 GHz, FSB 533 MHz, 1 MB L2 Cache

Intel Core Solo

Single core version of the Core Duo and successor of the Intel Pentium M. The performance is comparable with the equivalent clocked Pentium M (somewhat faster because of a few improvements).

A typical T1200 model works at 1.5GHz, with 667MHz FSB, and 2MB L2 Cache. A ultra low voltage model (example U1500) consumes only 5.5 watts of power.

Intel Mobile Pentium 4 M

Recent Pentium 4 M processors operate at 2.4 - 3.46 Ghz (earlier versions starting from 1.4 Ghz) with FSB 533 MHz (earlier versions offering 400) and 512KB to 1 MB level 2 Cache.

AMD Turion64 X2

64 bit dual core processor, code name Taylor (2 x 256 KB L2) and Trinidad (2 x 512 KB L2) offer DDR2-667 support, 31-35 W TDP, socket S1, 90 nm fabrication, and separated L2 Caches. Typical specifications for TL-66 are 2.3GHz clock, 2X512KB L2 cache, and 35 Watt power consumption.

AMD Turion 64

This is a derivative of the Athlon 64 with 32 and 64 bit support, integrated memory controller for PC3200 memory, 2 variants ML with 35 Watt and MB with 25 Watt consumption.

AMD Mobile Athlon 64

2700+ (1,6 Ghz) - 4000+ (2,6 Ghz). The rating is comparable with the clock rates of Pentium 4 M. It is a 32 and 64 bit processor relative fast per megahertz and uses moderately much current (and produces heat). The top versions are DTR (Desktop replacement) versions for large laptops.

AMD Mobile Sempron

2800+ to 3000+ mobile Athlon 64 with reduced level 2 Cache; The rating is not comparable with Athlon 64 Rating. A 3000+ Athlon 64 is faster than a 3000+ Sempron. There is no 64 bit support.

AMD Mobile Athlon XP-M

Mobile version of the Athlon XP is comparable with Pentium 4, and somewhat slower than Athlon 64 with same rating and no 64 bit support.

Throttling

CPU throttling refers to slowing down of the processor when required. For example, if you want to conserve battery power in a laptop, you may want to slow down the CPU clock to reduce power consumed by the CPU, and thereby increasing the batter usage time. CPU throttling is also used to prevent overheating of the CPU.

Power Management

Notebook Operating Systems (predominantly Windows XP) offers several options to manage the power consumed by a laptop. The available options depends on the exact hardware configuration of the notebook.

To open Power Options (XP) in your laptop, go to Start > Control Panel > Performance and Maintenance > Power Options. Sometimes, it may be slightly different in your laptop, depending on the OEM version of the XP software.

Power Options in Windows XP allow you to control the power management features of:

Display
Shut Down, Hibernate, and Stand by
Low battery warnings

WiFi:

The wireless local area networks (WLAN) use radio waves for providing a secure and reliable connectivity. It is based on IEEE 802.11 standard, and operates in the unlicensed 2.4GHz and 5GHz radio bands, or both of them (dual band), depending on the data rate your wireless hardware is using. There are several specifications in the IEEE 802.11 standard family and new ones are occasionally added, although all of them use the Ethernet protocol and CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance).

A WiFi (Wireless LAN) adapter may also be attached externally using USB port. A USB WiFi adapter uses USB port for this purpose.

Basic Wireless LAN configuration consists of the following:

The name of the wireless local area network (called SSID)
Wireless working mode (infrastructure or ad-hoc, see below)
WEP key (for data encryption, only if necessary)

Two most commonly used wireless LAN configurations are given below:

Ad-hoc mode
Infrastructure-mode:

Ad-hoc mode: Wi-Fi adapters on every machine using to the same WLAN make connections with every remote machine. This configuration is suitable for small networks.

Infrastructure mode:

Wi-Fi adapters on every machine using the same WLAN connects to the same access point, which in-turn links all the remote machines into one network.

Download practice tests: A+ Essentials 220-601, A+ IT Technician 220-602, A+ Remote Support Technician 220-603, A+ Depot Technician 220-604