Personal computing is governed by two inexorable, and not unrelated, "laws":

• Moore's Law Processing power doubles every 18 months (from Gordon Moore,
  cofounder of Intel).
• Parkinson's Law of Data Data expands to fill the space available for
  storage (from the original Parkinson's Law: Work expands to fill the time
  available).

These two observations help explain why, when the computers we use are
becoming increasingly powerful, our day-to-day tasks never really seem all that
much faster. The leaps in processing power and memory are being matched by the
increasing complexity and resource requirements of the latest programs. So the
computer you're using today might be twice as muscular as the one you were using
a year and a half ago, but the applications you're using are twice the size and
require twice as many resources.

Windows fits neatly into this scenario. With each new release of Microsoft's
flagship operating system, the hardware requirements become more stringent, and
our computers' processing power is taxed a little more. Windows Vista is no
exception. Even though Microsoft spent an enormous amount of time and effort
trying to shoehorn Vista into a minimal system configuration, you need a
reasonably powerful computer if you don't want to spend most of your day cursing
the dreaded hourglass icon.

The good news is that Windows Vista's hardware requirements are nowhere near
as onerous as many people believed they would be. In fact, most midrange or
better systems purchased in the past year or two should run Vista without a
problem. The next few sections present a rundown of the system requirements you
need to meet in order to install and work with Windows Vista. Note that I give
both the minimum requirements as stipulated by Microsoft, and a set of
"reasonable" requirements that I believe you need to make working with Vista
more or less pleasurable.

Processor Requirements

Vista desktop minimum: 800MHz modern processor

For adequate Vista performance, you need at least a midrange processor, which
means an Intel Pentium 4 or Celeron, or an AMD Athlon or Sempron running at
2.663.0GHz. Faster is better, of course, but only if money is no object. Moving
up to 3.2GHz or 3.6GHz might set you back a few hundred dollars, but the
performance improvement won't be all that noticeable. You'd be better off
investing those funds either in extra memory (discussed below) or in a dual-core
processor.

Note

What does dual-core mean? It describes a CPU that combines two separate
processors, each with its own cache memory, on a single chip. (The cache
memory is an on-board storage area that the processor uses to store commonly
used bits of data. The bigger the cache, the greater the performance.) This
enables the operating system to perform two tasks at once without a
performance hit. For example, you could work in your word processor or
spreadsheet program in the foreground using one processor, while the other
processor takes care of a background spyware or virus check. Current
examples of dual-core processors are the Intel Pentium D series and Pentium
Extreme Edition, and the AMD Athlon 64 X2.

The 64-bit processors are becoming more affordable, and they run the 64-bit
version of Vista like a dream (one of my Vista test machines was 64-bit, and it
was a pleasure to use). Look for a 64-bit Pentium 4 or any of the several x64
chips available from AMD. Note, however, that although these 64-bit machines can
run 32-bit applications without a performance hit, those programs will not run
any faster with the wider bus. To see a speed boost with your applications, you
have to wait for 64-bit versions of
Windows Vista and the applications you
intend to run on it.

Memory Requirements

Vista minimum: 512MB

You can run Vista on a system with 512MB of RAM, but the performance will be
quite slow. Admittedly, I've been running beta versions of Vista, which are
always slower than release versions because they contain debugging code and are
works-in-progress as far as optimization goes. However, I believe that, for most
people, 1GB is a more realistic minimum for day-to-day work, and that's how much
RAM Microsoft recommends for "Windows Vista Premium Ready" systems.

If you regularly have many programs running at the same time, or if you use
programs that manipulate digital photos or play music, consider moving up to
1.5GB. If you do extensive work with large files such as databases, or if you
use programs that manipulate digital videos, 2GB should be your RAM goal.

Note, however, that if you select a 64-bit processor, you should
seriously consider upgrading your system RAM. The conventional wisdom is that
because 64-bit machines deal with data in chunks that are twice the size of
those in 32-bit machines, you need twice the memory to take full advantage of
the 64-bit advantage. So if you'd normally have 1GB of RAM in a 32-bit machine,
opt for 2GB in your 64-bit computer.

Finally, consider the speed of the memory. Older DDR (double data rate)
memory chips typically operate at between 100MHz (PC-1600) and 200MHz (PC-3200),
while newer DDR2 chips run between 200MHz (PC2-3200) and 533MHz (PC2-8500). The
up-and-coming DDR3 chips will operate at between 400 and 800MHz, which is a
substantial speed boost and should improve Vista performance noticeably.

Note

Memory module numbers such as PC-3200 and PC2-8500 tell you the
theoretical bandwidth of the memory. For example, PC-3200 implies a
theoretical bandwidth of 3200MBps. To calculate theoretical bandwidth, you
first multiply the base chip speed by 2 to get the effective clock speed.
(Modern memory is double-pumped, which means data is transferred at the
beginning and the end of each clock cycle.) You then multiply the effective
clock speed by 8 (because the memory path is 64 bites wide and there are 8
bits in each byte). So a 100MHz chip has an effective clock speed of 200MHz
and, therefore, a theoretical bandwidth of 1600MBps, so it is called PC-1600
memory.

The System Rating

One of the new features in Windows Vista is a system rating that Vista
calculates for each computer on which it's installed. This rating appears in the
System window (on the Start menu, right-click Computer and then click
Properties). The rating is a numeric value that's based on the ratings given to
your computer's processor, how much RAM is installed on your system, your
graphics card and RAM, and the GPU's gaming graphics performance.

Why would Microsoft calculate such a rating? Certainly, it's not to let you
know whether your machine is capable of running Vista, because of course you
need to install and run Vista to see the rating. Instead, the system rating is
part of the performance calculations that the Windows System Assessment Tool
(WinSAT) generates. This tool analyzes your system so that applications that
support WinSAT (particularly games) can enable or disable certain features based
on their performance.

Storage Requirements

Vista hard disk free space minimum: 15GB

The disk space requirements depend on which version of Vista you're
installing, but count on the new OS requiring at least 15GB free space to
install. The OS will use perhaps another few gigabytes for the storage of things
such as the paging file, System Restore checkpoints, Internet Explorer temporary
file, and the Recycle Bin, so Vista will require at least 20GB of storage.

These days, of course, it's not the operating system that usurps the most
space on our hard drives; it's the massive multimedia files that now seem to be
routine for most of us. Multimegabyte digital photos and spreadsheets, and even
multigigabyte database files and digital video files are not unusual.
Fortunately, hard disk storage is dirt cheap these days, with most disks costing
lessoften much lessthan a dollar a gigabyte.

Note, too, that the type of hard drive can affect performance. An older IDE
drive that spins at 5,400RPM will be a significant performance bottleneck.
Moving up to a 7,200RPM drive will help immeasurably, and a 10,000RPM drive is
even better if you don't mind the extra expense. You should also consider moving
from the older, parallel IDE technology to the new Serial Advanced Technology
Attachment (SATA) drives, which are at least theoretically faster (with
data-transfer rates starting at 150MBps). Look for a SATA drive with an 8MB
cache and Native Command Queuing (NCQ).

Note

Native Command Queuing (NCQ) is a relatively new hard-disk technology
aimed at solving a long-standing hard-disk performance problem. Requests for
hard-drive data are stored in the memory controller and are handled in
sequence by the disk's on-board controller. Unfortunately, whenever the
controller processes requests for data that is stored in areas that are far
away from each other, it causes a significant performance hit.

For example, suppose request 1 is for data stored near the start of the
disk, request 2 is for data near the end of the disk, and request 3 is again
for data near the start of the disk. In a typical hard disk, the read/write
heads must travel from the start of the disk to the end, and then back
again, processing each request in the order it was received. With NCQ, the
controller reorders the requests so that the 1 and 3, which are close to
each other, are carried out first, and only then is the distant request 2
carried out.

Finally, you should also bear in mind that one of Windows Vista's new
features is the ability to burn data to recordable DVDs. To take advantage of
this, your system requires a DVD burner, preferably one that supports both the
DVD-RW and DVD+RW disc formats (that is, a DVD±RW drive).

Graphics Requirements

Vista graphics memory minimum: 32MB

You'll be learning a lot more about Vista's graphical underpinnings in
Chapter 3, "The Windows Vista Interface." For now, however, it's important to
note that Microsoft is taking a sensibly cautious route to graphics
requirements. Vista's interface is graphics intensive, but it will be smart
enough to adopt a less intensive interface based on what your PC can handle.

Whether Vista holds back on the visual bells and whistles depends on whether
you have a separate AGP or PCI Express graphics adapter (as opposed to an
integrated motherboard graphics chip), the capability of the card's graphics
processing unit (GPU), and how much graphics memory the card has on board:

• If Vista detects a low-end card, it defaults to the Windows Classic
  theme, which offers a Windows 2000like interface.
• If Vista detects a card with medium-range capabilities, it uses the new
  Aero theme, but without the Glass effects (such as transparency).
• If Vista detects a high-end card, it defaults to the full Aero Glass
  interface.

To get the beautiful Aero Glass look as well as the new 3D and animated
effects, your system should have a graphics processor that supports DirectX 9,
Pixel Shader 2.0 (in hardware, not as a software emulation), and 32 bits per
pixel, and comes with a device driver that supports the new Windows Vista
Display Driver Model (WDDM). (If you purchase a new video card, look for the
Windows Vista Capable or Windows Vista Premium Ready logo on the box. If you
just need to upgrade the driver for an existing graphics card, look for "WDDM"
in the drive name or description.)

The amount of onboard memory you need depends on the resolution you plan to
use (assuming you're using a single monitor; for dual monitors, double the
memory):

• If you'll be using a basic 800x600 or 1024x768 resolution, 32MB is
  enough.
• If you want to run up to 1280x1024, then you need at least 64MB.
• If you want to run up to 1920x1200, then you need at least 128MB.

Before the final release of Vista, it wasn't clear whether any integrated
graphics chips would support the full Aero Glass interface, although I've seen
reports that some integrated graphics hardwaresuch as the Intel 945 and the ATI
Radeon XPress X200can handle Aero Glass.