Dual Athlon FX Fantasies
Is it possible to use FX-51 CPUs in a dual-proc setup?
The Maximum PC Lab investigates74 MAXIMUM PC JUNE 2004
L
ike many technophiles, few things
get us worked up like hot CPU-on-
CPU action. So, needless to say,
when our dual-Opteron setup (built for
this month’s Speed report on page 28)
blew away our benchmark tests, we got
all hot and bothered. And we started
fantasizing about running a dual-CPU
rig at home.
Unfortunately, setting up a dual-
processor rig isn’t as cheap or accessible
as it used to be. Five years ago, you could
build a relatively affordable dual-Pentium
III box, but those days are long gone.
Intel ended the poor-boy DP ride when it
introduced the Pentium 4, which lacked
dual-CPU support. This meant that if you
wanted a dual-processor box, you had to
pay for it in the form of the much more
expensive Intel Xeon CPUs.
In the AMD camp, fans of dual-
processor systems have long championed
the Athlon MP for its low price and great
performance. Like Intel, AMD also tried
to lock down dual usage when it released
the new Athlon XP, but users soon found
hacks to unlock its potential for use in
dual-processor motherboards. Meanwhile,
the Opteron has been the company’s
official dual-proc CPU, and comes in
the 100, 200, and 800 series; the 100designates a single processor,
the 200 designates dual-proc
support, and 800 means you can
use eight CPUs in one PC. (Dual
Athlon MPs, of course, went out of
style last year when AMD introduced
the final bin speed for the proc: the
Athlon 2800+.)
But what about the FX-51? The short
history of the FX is that AMD wanted a
punchier chip to compete with the P4,
so it took the fastest Opteron chips off the
fab and renamed them Athlon 64 FX. This
combined with the fact that the FX-51
will drop in price as faster clock speeds are
released made us wonder: Is it possible to
use two FX-51s in a dual motherboard?
AMD has long denied this
functionality, but we decided to find
out for ourselves. We yanked one of
the Opteron 248 CPUs out of the Tyan
Thunder K8W mobo we used in this
month’s Speed trial and added an Athlon
64 FX-51. Because the 248 and FX-51 both
run at 2.2GHz, we didn’t anticipate any
problems. When the machine actually
posted, we became giddy—had we just
caught AMD telling fibs?
Unfortunately, we soon discovered that
even though the PC booted into Windows
XP, it only recognized one processor—theOpteron 248. It was as though the Athlon
64 FX wasn’t even installed. AMD, it turns
out, wasn’t pulling our IDE cables; the FX
really doesn’t work in dual mode. Damn!
But it’s not like building a dual box
would be cheap, anyway. The Tyan
Thunder K8W costs $500 and requires
an expensive EPS12V power supply like
PC Power and Cooling’s TurboCool
510 Deluxe. Dual rigs also slurp down
electricity; just turning on the dual-Opteron
box and watching it idle with no activity in
Windows uses roughly twice the power of a
single-processor machine.
Perhaps the low-cost dual processor is
really just a fantasy after all—for now, at
least. Rest assured that we’ll be investigating
more opportunities for steamy CPU-on-
CPU action in the future.Want to test wireless router performance the Maximum PC way?
Analyzing wireless networking hardware isn’t as straightforward as
running videocard or CPU benchmarks, but we devised a suite of tests
that produce real-world, repeatable results. Here’s how it’s done:➤ First, we set up a private network that’s disconnected from the
Internet and any other network. One PC is connected to the router
using standard 100baseT Ethernet, while another PC is connected via
the wireless network. We enable 128-bit WEP to more closely emulate
real-world conditions.
➤ Next, we transfer a compressed MPEG-2 video file that’s larger than300MB from a Windows shared folder on the wired machine to the
wireless machine and measure how long it takes to transfer.
➤ Once that’s done, we transfer the file back to the wired machine’s
shared folder and measure the amount of time it takes.
➤ After performing these tests, we connect the router to the Internet and
check to see if it has features such as VPN support, a firewall, port forward-
ing, and a virtual DMZ. A good router will have all this and more—if these
features are present, we turn them on to see how they work.
➤ We calculate the final verdict by factoring in performance, features,
and the hardware’s overall ease of installation.How We Test: Wireless Routers
Our lustworthy goal: to get two
Athlon 64 FX CPUs to run in this
Tyan Thunder mobo.