Within Family Differences

CPU design isn't static. Over the years, each architecture has spawned multiple CPU designs. New models frequently introduce new features, typically while maintaining compatibility with older designs. Therefore, old software can run on new CPUs, but to take full advantage of the new CPUs, software must be recompiled. This recompilation sometimes makes binaries incompatible with the older CPUs. The upcoming section, "Improving Performance with Compile-Time Options," describes some of the specifics of how to do this job.

Within the IA-32 family, there are several different general levels of performance, which are often referred to by numbers that relate to Intel's original naming convention for these CPUs. The lowest-numbered IA-32 CPU is the ¡386. (Earlier CPUs in this line, such as the ¡286, used 16-bit architectures. These CPUs are x86 CPUs but not IA-32 CPUs.) Intel, AMD, and Cyrix (now bought out by VIA) all produced ¡386 and i486 CPUs. With the next level, Intel began naming its CPUs, starting with the Pentium; therefore, this CPU is sometimes called the ¡586. AMD and Cyrix also produced ¡586-level CPUs, although their design details differed from the Pentium's.

Today, the best IA-32 CPUs are the Pentium 4 and the AMD Athlon, while Intel's Celeron and AMD's Duron occupy a slightly lower tier. Each of these CPUs is more than capable of running Linux. Because new CPU models emerge so quickly, your best bet for obtaining relative performance information is to check magazine reviews or online hardware sites, such as Tom's Hardware Guide (http://www.tomshardware.com).

Linux software packages (described in more detail in Chapter 11, "Managing Packages") often include an architecture code in their filenames. For IA-32 systems, this code is usually ¡386, but it may be ¡586, ¡686, or even something more specific, such as athlon. Installing a package with a code for a lower-grade CPU than you own isn't a problem, but installing a package intended for a higher-grade CPU or a specific CPU from another manufacturer may cause poor performance or program crashes. For instance, you shouldn't try to use an athlon package on a Pentium-class or Pentium 4 CPU.

0 0

Post a comment