You’ll fi nd Intel VT in about half of Intel’s
Core 2 Duo desktop processors (the E6600
through E6850, and the E8200 through E8600),
all of its Core 2 Quad and Core 2 Extreme
desktop processors, and its quad-core Xeon and
Itanium server procs (the Itanium version is
formally known as Virtualization Technology for
IA-64). Intel’s upcoming Core CPU will feature
Intel’s VT-d (Virtualization Technology for Di-
rected I/O), which will enable guest virtual ma-
chines to directly use peripheral devices, such
as a network interface device. Although AMD-V
and Intel VT are similar, they’re not compatible;
a hypervisor that supports only AMD-V will not
take advantage of the virtualization extensions
in an Intel CPU and vice versa. Fortunately,
hypervisors that support both sets of extensions
are common.
APPLICATIONS FOR VIRTUAL
MACHINES
What are virtual machines good for? The most
common application today is server deploy-
ment. A virtual machine can make much more
effi cient use of a server’s hardware by running
several instances of the same operating system
and the same applications in parallel, or even
diff erent operating systems and applications.
In either scenario, each instance thinks it has
sole access to the hardware and behaves accord-
ingly. The hypervisor dynamically assigns virtual
resources (such as processors and memory) to
physical resources so that the hardware is never
left idle. Virtual machines are also useful as test
platforms: System designers and application
developers can experiment with new code
without disrupting or interfering with the usual
production environment.
But virtual machines are useful for indi-
vidual users, too. Experimenting with diff erent
operating systems—such as Linux—on one
computer is just one example. Trying out new
soft ware—especially shareware—is another. If a
program renders your system unstable, you can
blow away the virtual machine without any con-
sequences. Or if you’re paranoid about privacy,
you could create a virtual machine explicitly for
web browsing: Isolate all your personal informa-
tion on one installation that you never use for
web surfi ng. Fire up the virtual machine when
you do want to browse the web and tracking
cookies, spyware, and any other Internet detri-
tus you encounter will be trapped there, where it
can’t harm your production environment.
Getting started with virtual machines is
certainly cheap enough: Several programs are
available for free, including Microsoft ’s Virtual
PC and Sun Microsystems’s VirtualBox (the latter
of which is capable of running Windows as a
guest operating system running on Linux).
AUTOPSYBelkin Vision N1 Router
One of the features we like about Belkin’s Vision N1 router is the
large LCD that keeps you informed of your network’s status. Let’s see
what goodies are inside.http://www.maximumpc.com|DEC 08 |MAMAMAXIMXIMXIMXIMUUUUMMPPPCC| 71
SUBMIT YOUR IDEA Ever wonder what the inside of a power supply looks like?
Don’t take a chance on destroying your own rig; instead, let us do the dirty
work. Tell us what we should crack open for a future autopsy by writing to
[email protected].rected I/O), which will enable guest virtual ma-
as a network interface device. Although AMD-V
and Intel VT are similar, they’re not compatible;
a hypervisor that supports only AMD-V will not
take advantage of the virtualization extensions
hypervisors that support both sets of extensions
What are virtual machines good for? The most
ment. A virtual machine can make much more
effi cient use of a server’s hardware by running
several instances of the same operating system
In either scenario, each instance thinks it has
sole access to the hardware and behaves accord-
ingly. The hypervisor dynamically assigns virtual
physical resources so that the hardware is never
left idle. Virtual machines are also useful as test
without disrupting or interfering with the usual
vidual users, too. Experimenting with diff erent
soft ware—especially shareware—is another. If a
program renders your system unstable, you can
blow away the virtual machine without any con-
sequences. Or if you’re paranoid about privacy,
you could create a virtual machine explicitly for
web browsing: Isolate all your personal informa-
web surfi ng. Fire up the virtual machine when
cookies, spyware, and any other Internet detri-
tus you encounter will be trapped there, where it
WIRELESS MAC/BASE-
BAND CHIP The Atheros
AR5416 is a baseband and
Media Access Controller
(MAC) chip. This provides
the router with the ad-
dressing and channel ac-
cess control mechanisms
needed for a device to
transmit on and share the
network’s capacity.CPU The Atheros AR7141 is
the router’s CPU. This one
is a 32-bit model clocked at
400MHz. It drives the display,
serves as the interface to
memory, and handles commu-
nication over the internal PCI
bus and the USB 2.0 bus, among
other things.GIGABIT ETHERNET SWITCH
The Vitesse VSC7385 serves
as the Vision N1’s integrated
gigabit switch. This is one
of only two components (the
other being the transistor that
is part of the router’s power
circuit) that requires a heat-
sink for additional cooling.WAN PORT
This Ethernet
port connects
the router to your
Internet gateway (i.e.,
your DSL or cable mo-
dem). WAN is an acronym
for Wide Area Network.ETHERNET PORTS These Ethernet
ports are connected to the router’s
gigabit switch, which enables mul-
tiple devices to share access to your
Internet gateway.LCD One of the Vision N1’s key selling points is this large
display that keeps you informed of your network’s status
and your connection to the Internet.FLIPSIDE