Since the theme of this issue is "Computing on the Road," let's take a look at the
current crop of processor chips that power today's notebook computers. The processor
chip is the main central processor unit (CPU), which performs all the calculations
that makes the computer work. In other words, it's the computer's brain, which does
all its "thinking." The newest processors are all designed to overcome some inherent
problems with notebook computers: speed, power consumption, and connectivity. Notebook
processors have typically lagged behind desktop processors due to slower clock speeds
and slower memory buses. Increases in processor speed not only consumes more power
(shortening battery life), they also generate more heat. Finally, connecting notebook
computers to the external world has gotten easier as wireless networking becomes more
popular. As we look at each type of processor, we'll consider how it deals with these
The Pentium 4-M was Intel's first attempt to adapt its Pentium 4 to notebooks. Its
design focused on saving power, which it does well. But it lacks the speed of the
desktop Pentium 4, and costs more. The fastest Pentium 4-M has a 2.5 GHz clock.
The Mobile Pentium 4 is very similar to the desktop Pentium 4, but consumes about
25% less power. Its fastest version has a 3.06 GHz clock, the same as the fastest
desktop Pentium 4, but without the hyper-threading feature that adds considerable
speed to the desktop model. And the Mobile Pentium 4 chip costs more than the
desktop Pentium 4.
Intel's most recent, and highly advertised new processor chip is the new Centrino.
Although its name sounds like a sub-atomic particle, the Centrino is actually a suite
of three chips. The processor chip is the Pentium M, which is designed from the ground
up as a notebook chip. It uses a 1 MB cache to fetch data from the notebook's memory
faster. That gives its 1.6 GHz version performance equal to a 2.4 GHz Pentium 4-M. The
fastest Pentium M chip has a 1.7 GHz clock speed.
But Centrino includes more than the Pentium M chip. A new chipset called the Intel 855
takes care of the essential functions on the motherboard. Supporting up to 2 GB of RAM,
the Intel 855 also provides highly desirable USB 2.0 support. Running 40 times faster
than a USB 1.1 bus, the USB 2.0 bus is essential to adding high-speed accessories, like
printers, scanners, DVD burners, and today's high-speed CD burners.
Finally, Centrino includes built-in support to 802.11b wireless networking (sometimes
called WiFi) via an Intel PRO/wireless 2100 network connection chip. This chip reduces
power required to run a wireless connection, and lets a notebook manufacturer build in the
wireless network circuitry. That means you don't have to give up a PCMCIA expansion port
to the WiFi card.
Intel's main rival, AMD, is not ignoring the notebook market, either. It recently announced
Athlon XP-M processors designed for notebook computers. There are three versions of the
Athlon XP-M processor: 1900+, 2000+, and 2800+ models. Remember, the numeric rating of
Athlon processors is intended to designate equivalent performance in an Intel processor,
so the 2800+ processor should be roughly equivalent to a 2.8 GHz Pentium 4. The 1900+ and
2000+ chips are designed for use in slim, lightweight notebooks, while the 2800+ chip is
designed for high performance notebooks.
Although AMD chips are compatible with WiFi networks, there is no direct support akin to the
Intel PRO/wireless 2100 chip.
Listen to Your Laptop
Many modern notebook computers include DVD drives, which can play standard DVD movies that
you can rent (or buy) at your local Blockbuster Video. My notebook computer keeps me
entertained during trips on which I have lots of free time (e.g., on airplanes) and few
recreational opportunities. But when I watch a movie, the notebook's tiny (and tinny)
speakers don't do justice to the sometimes spectacular soundtracks on many DVDs. So I pack
a set of headphones in my notebook case. Plugging those into the speaker output jack on my
notebook yields much better sound, although it's far from audiophile quality. Similarly,
when I want to listen to music CDs, I can pop one into the notebook DVD drive, and play
music through the headphones. But increasingly, I have become dissatisfied with the
quality of sound through the headphones. So I did what many audiophiles do: I consulted
the HeadRoom Corporation, a company that specializes in amplifiers and other accessories
HeadRoom offers two amplifiers designed for mobile listening. The HeadRoom AirHead amplifier
is only slightly larger than a cassette tape, and runs about 40 hours on three AAA batteries.
You can get an AC adaptor at most electronics shops (e.g., Radio Shack). According to
HeadRoom, it produces "clean, clear, massively enjoyable audio reproduction." The price is
$120. For a little more money ($200), HeadRoom offers the Total AirHead amplifier (Figure 2),
with upgraded internal components. In its refreshingly direct manner, HeadRoom acknowledges
that the Total AirHead will make a difference with only the best headphones, so unless your
headphones cost in the neighborhood of $300 or more, the basic HeadRoom amp is probably the
better choice. Plug the AirHead into notebook's audio output jack and your headphones into
the AirHead. As a final enticement, HeadRoom includes its proprietary circuit that creates
a more believable stereo image from headphones, instead of the common
sound-in-the-middle-of-your-head image. This circuit should make music sound more like it's
coming from speakers than headphones.
So what if you don't have headphones, but would like to try some? When you visit any
electronics or music store, you'll see there's an enormous choice. For notebook users,
space is at a premium, since they have to store headphones in their notebook case. For
that reason, I recommend considering headphones that fit into the ear like earplugs. Prices
start at around $10, but for more money, you can get some decent headphones. The Etymotic
ER-4 in-ear headphone sells for $269, and is one of the best headphones you can get. If
you're like me and not ready to spend that much on headphones for occasional use, Etymotic
makes a lower cost ER-6, and Shure (maker of phono cartridges and professional audio equipment)
makes an E2C model, both of which cost about $100. That's still a lot of money, but way less
than $269. The in-ear headphones also provide better isolation (around 20db) from the outside
environment, which provides sonic comfort in noisy environments like airplanes. HeadRoom
sells all these headphones, and offers package deals if you buy
headphones and an amplifier at the same time.