Choosing and Buying Components - Building the Perfect PC - page 47

much larger). If you're installing multiple video adapters in an NVIDIA SLI
(Scalable Link Interface) or AMD/ATI CrossFireX configuration, make sure
to use a power supply that is certified for such use.

Recommendedpowersupplybrands
There are many good power supply brands, but Antec ( http://www.antec.
com ), PC Power & Cooling ( http://www.pcpower.com ) , and Seasonic ( http://
www.seasonicusa.com ) stand out from the crowd. All three companies offer a
wide range of power supplies to fit various needs.

Processor
A few years ago, if we checked an online PC component vendor for desktop
processors, there would have been maybe eight or nine Intel processors on of-
fer and about the same number of AMD processors. When we started working
on this section, we checked the NewEgg desktop processor page. There were
44 AMD processors available, ranging in price from $36 to $296, and 42 Intel
processors, ranging in price from $41 to $1,000. That's a lot of options. How
can AMD and Intel possibly make that many different processors? And how
can anyone make the best choice among 86 processors ranging in price from
$36 to $1,000?

The short answer is that AMD and Intel really don't make all that many differ-
ent processors. They each make only a few significantly different models, but
offer those models in various speeds and with different combinations of minor
features. It's like buying a car. The base model may have a dozen options avail-
able, and by the time you total up all the available permutations, that base
model can be ordered in thousands of different configurations.

A particular processor series may be available in numerous models that vary in
speed, number of cores, number of threads per core, amount of L3 cache, pow-
er consumption, and so on. There is also frequently pricing overlap between
models from different processor series. For example, the day we checked, no
less than four different Intel processors were selling for exactly the same price,
$199.99. Table 2-1 lists them.

Table 2-1. Four $200 Intel processor models

Model Cores Threads Speed L3 cache Process Socket Power

Core 2 Quad
Q9300

4 4 (1/core) 2.5 GHz 6 MB 45 nm LGA 775 95W

Core i5-660 2 4 (2/core) 3.33 GHz 4 MB 32 nm LGA 1156 73W

Core i5-661 2 4 (2/core) 3.33 GHz 4 MB 32 nm LGA 1156 87W

Core i5-750 4 4 (1/core) 2.66 GHz 8 MB 45 nm LGA 1156 95W

As Intel was fully aware when it set the prices for these four processors, their
overall performance is very similar. Will a quad-core processor with a slower
clock speed but more L3 cache outperform a dual-core processor with a faster
clock speed and less L3 cache, or vice versa? Will a dual-core processor that
runs two threads per core outperform a quad-core processor that runs only