MaximumPC 2007 02

I

f you can’t figure out which way to configure your single-

processor motherboard to take advantage of dual-channel

memory, you’ll truly be stumped by AMD’s Quad FX, which

gives each of its dual-core Athlon 64 CPUs its own memory

bank. In other words, dual dual-channel RAM.

With four DIMM slots available and a host of ways to configure

them, I sat down with a box of memory modules to discover how to

set up the platform for optimal performance.

First, I populated our Asus L1N64-SLI with four 512MB DIMMs

of DDR2/800. With the RAM timings manually set, I ran through a

handful of benchmarks, shut the box down, and swapped the four

512MB DIMMs for two 1GB DIMMs. I put these two DIMMs in the

memory bank for the primary CPU, which meant both procs were

sharing RAM, but the RAM was running in dual-channel mode.

When I went for the third configuration—a single 1GB DIMM for

each processor, which should have given each CPU 1GB of RAM in

single-channel mode—the machine spit up a hairball. Interestingly,

the board also balked when I put only two DIMMs into the slots

assigned to the second CPU.

I was surprised to find that the machine performed slightly

better with the pair of 1GB DIMMs running in dual-channel mode

than when each proc had its own RAM pool. Why? One reason

could be that our benchmarks just aren’t that memory-bandwidth

intensive, so they may not actually need the extra bandwidth that

running dual dual-channels gives you. Another factor may be

how the memory controller works with double-sided DIMMs (the

larger 1GB sticks) versus the single-sided DIMMs (the 512MB

modules). Additionally, AMD has already said that Windows XP’s

Non Uniform Memory Access capability is gimped and that Vista

yields higher performance when the OS has to reach across dif-

ferent buses to get to RAM. We’ll test that theory when Vista’s

drivers stabilize.

In the end, if you have the budget, I recommend that you con-

figure your board with four double-sided DIMMs. If you don’t have

the budget, go with two double-sided DIMMs in the first CPU’s bank

until you can afford the other two. I’d avoid using low-density single-

sided DIMMs since this configuration hurts your upgrade path, and

your performance too.

I

n order to evaluate the Zune, it’s necessary to also assess the

Zune Marketplace, Microsoft’s online music store. The Zune isn’t

a bad digital media player, but the Zune Marketplace is an abso-

lute embarrassment.

Who else but Microsoft could cook up a semi-half-assed DRM

scheme like PlaysForSure; convince a big slice of the record industry,

oodles of subscription services, dozens of manufacturers, and an ass-

load of consumers to go along with it; and then bring out its own incom-

patible product to compete against it.

We despise DRM no matter what guise it comes in, but at least

PlaysForSure doesn’t handcuff us to a single brand of player and a

single online music service the way

the Zune (and iPod, for that mat-

ter) does. With PlaysForSure, we

can gorge ourselves at Rhapsody’s

smorgasbord, nosh on the ultra-

high-bitrate fare from Music Giants,

or nibble at Napster, Yahoo, Virgin,

or a number of other online services.

But we can’t do that with the Zune,

because Microsoft has cooked up

a completely new and incompatible

DRM scheme for the device.

Microsoft shackles Zune buyers to the Zune Marketplace in much

the same way Apple enslaves its online music buyers to its iTunes

Store—and for the very same reason: greed. Like Apple, Microsoft

wants to reap all the profits from the sale of both its player and the

music that will be put on it. But after perusing the shockingly spare

inventory at the Zune Marketplace, we’re left wondering if Microsoft

forgot to stock its shelves, or if the music industry collectively told

the kids in Redmond to take a hike.

Michael Brown

Shops at Microsoft’s Zune

Marketplace

And discovers the best way to configure the dual

dual-channel RAM in AMD’s Quad FX

Did someone forget to stock the shelves

before opening the store?

62 MAXIMUMPC february 2007 february 2007 MAXIMUMPC 63

in the lab Real-WoRld testing: Results. analysis. Recommendations

Anyone considering buy-

ing a Zune should first stroll

through the empty aisles of

the Zune Marketplace. Come

on, Microsoft, just one re-

lease from the Cramps?

The four DIMM slots in the Quad FX platform feed two indepen-

dent memory controllers in the CPU cores.

GORDON MAh Ung

Plays

Memory Roulette