[ The PC Guide | The
PC Buyer's Guide | Designing and Specifying PC Systems and
Components | Notebook PC Specification Issues ]
Key Notebook Design Characteristics and Tradeoffs
As I mentioned, notebook PCs are an exercise in compromises.
Taking an entire PC and cramming it into a box approximately the size of a textbook
doesn't come easy. I consider the engineers who create notebooks to be the "magicians
of the PC world", constantly cramming more power and more features into the same
amount of space--and sometimes even less space.
Still, there's only so much you can put into any design with sacrificing something
else. This means that in considering what you want from a notebook's design, you have to
make tradeoffs. Here are some of the key design characteristics of notebooks and the
tradeoffs they make against each other and other important system attributes:
- Size and Weight: To get smaller size and lower weight one must make a lot of
compromises in other design matters. I discuss this in some detail where I introduce different notebook classes.
- Cost: The more performance, capacity and features in the notebook, the more
you'll pay, and the differences are magnified from what they are in the desktop world. You
also pay more for quality, and that's very important in the notebook world.
- Performance: Performance trades off against both cost and size (larger notebooks
are usually more powerful than smaller ones). It also trades off against other attributes.
One is battery life, because faster CPUs, larger hard disk drives and so on use more
power. Another is cooling, which is an important reliability issue for notebooks, and is
made more difficult by faster components.
- Battery Life: Battery life (how long the battery lasts on a charge) trades off
primarily against size and cost (because to reduce weight or cost many notebooks use
smaller batteries) and also against performance and features (because more and faster
components often require more power to run). This is one of the reasons some notebooks
have SpeedStep processors that run at a slower speed when the notebook is on the battery.
Battery life is a matter of great import to many notebook users, but not of much relevance
to others--it all depends on whether you use the machine "in transit" a great
deal, or not.
- Cooling: As PC performance increases, more components create more heat. At one
point no components in the PC needed special cooling features; then just CPUs did. Now on
some desktops heat sinks are required for the CPU, the video card and even the hard disk.
In the notebook world matters are often worse, because the cramped environs of the
notebook box don't allow for easy cooling. Increasing performance or reducing size makes
cooling more difficult. (This is another reason why Intel created SpeedStep, which reduces
CPU speed and voltage when running on the battery.) Note that cooling is primarily a
reliability issue but also affects comfort, especially if you actually use your notebook
as a "laptop". They can get quite hot on the legs. :^)
- Quality: As described in a previous section, quality is essential in a notebook.
It primarily trades off against cost: better units cost more than lesser ones.
In addition to these primary design characteristics and their tradeoffs, there are a
few other design issues to keep in mind when looking at notebooks:
- Expandability: Larger units generally come with more expansion and
interconnection options. These help increase the functionality of the system and also let
you use it more as you would a desktop.
- Modularity: Designs that are modular are superior to those that are not, because
they give you flexibility. Especially important is modularity when it comes to key
components that you might want to upgrade, such as the hard disk drive.
- Port Replication and Docking: Some designs come with a port replicator or docking
station (though this is usually an option that you pay extra for). These are hardware
units that connect to the notebook to improve its expandability and connectivity when the
laptop is "at home". These are often paired with smaller, lighter notebook
designs, and can give you the "best of both worlds": while traveling you have
reduced weight, and when at home you "dock" the machine and get access to your
standard external peripherals.
- Screen Size: For most notebook designs, the size of the screen is the deciding
factor in the size (but not necessarily weight) of the notebook as a whole. Most users
prefer larger screens to smaller ones, but you can't make a very small and light notebook
with a huge screen. Even smaller screens are of a pretty good size today, compared to the
8-9" screens of the early 1990s.
- Integrated Components: I prefer to avoid integrated
components for desktop units because they cause the design to be inflexible and
proprietary. For notebooks however, such designs can be a definite plus, when the
integrated components are of a fairly standard nature. For example, some notebooks have a
standard integrated V.90 56K modem; this is great because it saves you from having to
"waste" a PC Card slot on a PC Card modem. (Check in the BIOS setup of the
notebook to see if any integrated components can be disabled, in case you need to turn
Component Specification Issues
Home - Search
- Topics - Up