I
f you read our September 2006 Dream Machine feature you already
know about Intel’s shockingly fast Core 2 Extreme X6800 CPU.
Based on the company’s new Core microarchitecture, the C2E (and
its Clark Kent alter ego, the Core 2 Duo) marks Intel’s return to a
“brainiac” design that emphasizes performance per clock rather than
insanely high clock speeds (as characterized by the Pentium 4). In a
nutshell, the X6800 is “wider, faster, and cooler.” It’s wider because its
microarchitecture is designed to process four instructions per cycle
(versus three in the P4 and Athlon 64.) Faster describes the Core
CPU’s ability to process a 128-bit SSE instruction in a single cycle
instead of the two cycles its contemporaries require. And it’s designedto run cooler than its smoking-hot predecessors.
AMD, meanwhile, is betting that its stellar K8 microarchitecture
and the elegant design of its Hyper-Transport links as well as its on-
die memory controller—something Intel still lacks—will help the com-
pany remain the bad boy of computing. The latest Windsor core AM
chips upgrade the memory controller from Socket 939’s DDR support
to DDR2/800 RAM.
To help you in your next PC buying or building decision, we
weighed the costs and measured the benefits of both AMD’s and
Intel’s top-of-the-line procs.Intel Core 2 Extreme vs. AMD Athlon 64 FX-
Motherboard and
Chipset support
AMD’s Socket AM2 sup-
port is rolling along quite
well for the DDR2 versions
of the Athlon 64, and even
better, there’s no damned
confusion. Any AM
processor should work in
any AM2 motherboard.
Board support for the
Core 2 Extreme and Core
2 Duo is still in its infancy.
We’ve seen only two ship-
ping boards with Core
2 Duo/Extreme support
thus far: Asus’ P5W DH
Deluxe (reviewed on page
84) and the “304” version
of the Intel D975XBX. Of
course, consumers will
have a tough time figuring
out which boards are the
304 version. Winner:
athlon FX-Athlon 64 FX-
$1,030, http://www.amd.comFeatures The Athlon 64 supports SSE, SSE2, SSE3, NX, and of course, 3DNow!,
3DNow! Professional, and AMD64. The Core 2 Extreme includes SSE, SSE2, SSE3, NX,
Intel’s version of AMD64 (known as EM64T), and the new SSE4 instructions. This alphabet soup really
means that when it comes to enhanced instruction support, both CPUs are pretty equal.
Sure, only the Core 2 Extreme has SSE4, but that won’t be an issue for some time. The only features
that matter today are SSE1, 2, and 3, AMD64, and NX support.
Of course, there are a ton of potential features that may or may not ever materialize, and no one’s
talking about them. According to rumors, AMD snuck in the ability to make both cores in a dual-core
proc look like a single core to an application that cannot take advantage of dual-cores. Is it there?
There’s no way to know. We do know, however, that Intel mysteriously had support for Core Multiplexing
Technology in Core 2-compatible chipsets, and then quietly removed it from BIOSes. Is CMT the same
approach AMD is taking? We just don’t know. For now, we’re calling it a tie, but moves by either camp
could dramatically shift the balance. Winner: tiehead 2 head Two Technologies enTer, one Technology leaves
round^1
round 2
By goRDon Mah ung16 MAXIMUMPC october 2006
high-end Cpus