Datasheet
Identifying Purposes and Characteristics of Processors
35
motherboard. As a result, the grid of metallic contact points, called lands, on the bottom of
the CPU gives this format its name.
This discussion only scratches the surface of the topic surrounding chip
packaging and carriers. For more information on the various packaging for
chips, start with
ENWIKIPEDIAORGWIKI#ATEGORY#HIP?CARRIERS.
You can easily identify which component inside the computer is the CPU because it is
a large square lying flat on the motherboard with a very large heat sink and fan (as shown
earlier in Figure 1.12). Or if the CPU is installed in a Slot 1 motherboard, it is a large ½-inch-
thick expansion card with a large heat sink and fan integrated into the package. It is located
away from the expansion cards. Figure 1.28 shows the location of the CPU in relation to the
other components on a typical ATX motherboard. Notice how prominent the CPU is.
FIGURE 1.28 The location of a CPU inside a typical computer
CPU
Modern processors can feature the following:
Hyperthreading This term refers to Intel’s Hyper-Threading Technology (HTT). HTT is
a form of simultaneous multithreading (SMT). SMT takes advantage of a modern CPU’s
superscalar architecture. Superscalar processors are able to have multiple instructions oper-
ating on separate data in parallel.
HTT-capable processors appear to the operating system to be two processors. As a result,
the operating system can schedule two processes at the same time, as in the case of symmet-
ric multiprocessing (SMP), where two or more processors use the same system resources. In
fact, the operating system must support SMP in order to take advantage of HTT. If the cur-
rent process stalls because of missing data caused by, say, cache or branch prediction issues,
the execution resources of the processor can be reallocated for a different process that is
ready to go, reducing processor downtime.
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