Quad-Core Processor Forecast

For an updated look at the most recent CPUs, see Quad-Core Processor Buyer's Guide 2007.

Dual-core processors are barely out of the starting gate, and already Intel and AMD are racing to see who can be first to market with quad-core CPUs.

Both chip vendors have spewed forth a blizzard of announcements, though no actual quad-core microprocessors have yet shipped. Intel disclosed at its late-September developer forum that it's giving its four-way devices the brand name "Core 2 Quad." As for AMD, it has touted the tape-out of a quad version of its Opteron server CPU as well as the launch of a new quad-ready socket.

So, while it's early in the quad-core game, it's nevertheless difficult to tell the planned parts apart without a scorecard. Accordingly, we bring you a short but hopefully useful guide, which corrals all the publicly available processor information into one place. We've separated the upcoming chips into server and desktop categories. We've also included an image gallery containing slides from Intel and AMD, which provide information on the respective companies' roadmaps.

AMD Server: Socket-F Opterons

Despite the intense publicity surrounding Intel's revelations at IDF about its desktop "Kentsfield" processor, servers are likely to be the arena where quad-core computing gets its sea legs. That's because server operating-system software is generally more capable of exploiting multithreading and virtualization. Those features maximize CPU throughput by doling out tasks to keep all the cores humming along. As well, server users have more of a need to run heavy duty apps to power their ecommerce sites and customer-relationship management databases than do typical desktop PCers.

As the duel for bragging rights has played out so far this year, AMD announced its server quad-core plans first, but Intel says it will be first to ship. AMD's server offering will be a beefed up version of its Opteron.

In mid-August, AMD said it had taped out, or completed the design of the underlying silicon, of its four-core Opteron. The processor is scheduled to ship in the middle of next year.

The quad-core Opterons will also use AMD's new Socket F. This 1207-pin socket will support a faster interprocessor communications link and will also the processors to be hooked up to faster RAM.

Still unclear are the quad Opterons' specs for power dissipation and clock speed. Indeed, those numbers aren't publicly available for most of the upcoming quad-cores from both AMD and Intel. While the two vendors have shed some light on the former -- essentially saying that the thermal envelopes won't be much different from the existing dual-cores -- they've been pretty much mum on the latter.

The issue gets more interesting when one recalls that the original impetus for multicore was the inability of chip designers to increase the clock speed much beyond 3.0 GHz without pushing power dissipation into the red-zone region of 150-W and beyond.

AMD has stated that the quad-core Opterons will fit into the same thermal envelopes as the existing dual-core models. That would put the quads on par with most recent Rev. F Opterons, which come in three flavors, with maximum ratings of 103W, 95W, and 55W. Interestingly, that top dissipation number is down a little from the earlier Rev. E Opterons, which topped out at 110W. [Update: Oct. 5, AMD says that its quad-core Opterons will be available in versions with maximum ratings of 68-W and 95-W.]

In terms of clock-speed, the current, dual-core Opterons range from 1.8 GHz to 2.6 GHz. For a sense of what the speed quad-cores will have, one could look at AMD's recent statement that its "quad-core AMD Opteron processors are expected to be electrical-, thermal- and socket-compatible with the Opteron [Rev. F] processors." Expect the quad Opterons to be in the same 1.8-GHz to 2.6-GHz ballpark.

Indeed, in terms of marketability alone, it's unlikely that we'll see any quad-core Opterons with clock-speed specs slower than 1.8-GHz. A sales pitch offering slower processors, albeit with more cores, would make any marketeer fidgety, notwithstanding the reality that a quad-core with a pokier clock might have a higher throughput than a faster two-way.

From a broader microprocessor-design perspective, one can infer that the ability of AMD and Intel to push clock speeds while holding the line on power dissipation is the biggest challenge the companies' engineers face. Techniques like AMD's "Cool-n-Quiet" and Intel's SpeedStep technologies, which are supposed to ramp down the power when computing demands on the chip lighten up, will help. At the same time, both Intel and AMD are rushing to ramp up their next-generation 45-nm semiconductor fabrication processes, which by definition provide some breathing room in terms of power dissipation.

On this front, Intel may have an advantage in that it is farther along in its 65-nm processor than is AMD (which is currently ramping up 65-nm in its fabs). Thus Intel is presumably closer to bring up its 45-nm process. Over the next 18 months, this could change the dynamic from the current situation, where Intel's multicore processors are sometimes perceived to be more power-hungry than AMD's.

Intel Server: 'Clovertown'

The centerpiece of Intel's enterprise strategy will be a quad-core offering code-named "Clovertown." The processor will take its place at the head of Intel's Xeon server lineup.

Intel is heavily emphasizing the power characteristics of the chip, in an apparent nod to rising concerns about the cost of powering -- and cooling -- data centers.

"In November, we will introduce a quad-core Xeon, the first quad-core CPU in the industry for the high-volume market segments," Intel CEO Paul Otellini said in his keynote speech at IDF. "Beginning early next year, we'll introduce a lower-voltage version of that quad-core down at 50 watts, a 40 percent reduction from the standard voltage part that we'll introduce in November."

In hyping power specs, Intel seems to be taking a page from the marketing campaign AMD launched in May 2006, when it unveiled a billboard in Times Square focusing on the energy efficiency of its Opterons. (Here's a YouTube video showing that billboard.)

Intel's pledge of 50-W is aggressive, but undoubtedly doable since the company currently delivers a low-voltage, dual-core Xeon running at 2.33 GHz with a dissipation of 40W. Of course, the non-low-voltage Xeons come in at a higher thermal point, with dissipations variously specified as 65W, 95W, 130W, and 150W. Clock speeds range from 1.86 GHz to 3.5 GHz.

In terms of performance, the promises Otellini is making may well be putting Intel's engineers under the gun just as much as are their compadres over at AMD. "The quad-core Xeon will deliver 50 percent improvement over today's core microarchitecture -- the dual-core Xeon 5100 -- in the same power envelope," Otellini said in his IDF keynote. "That is, it goes into the same socket, in the same chassis, in the same power envelope, at a 50 percent improvement in performance."

Intel has received some criticism because Clovertown ties together two dual-core processors in a multichip package. (Some of that criticism has come from AMD, which says that its competing Opteron design will be what it's calling a "true quad-core," with four separate cores packed together onto a single silicon die.)

"This is a multichip package, but so what? I think you'd be misreading the market if you think people care about the packaging," Otellini was quoted by InformationWeek as saying following his IDF keynote.

The kerfuffle harkens back to similar criticism Intel received when it launched its first dual-core Pentiums. The Pentium D 8XX series placed two separate single-core processors on a piece of silicon. That design was soon updated to a true dual core, with the subsequent 9XX line.

AMD Desktop: 4x4, Native Quad

AMD's desktop plans are more difficult to nail down than are Intel's. Right now, the company is planning a two-step approach, in which it initially releases its 4x4 platform, which uses two dual-core processors to achieve four-way computing. That will be followed in the second half of 2007 by a true quad-core desktop processor.

The lag between the two is believe to stem from AMD's need to bring up its 65-nm process at its fabs in Germany -- something that's now in the works -- before it can ship the native quad-core chip.

The 4x4 platform, due out later this year, will link together two Athlon 64 FX dual-core processor via AMD's fast HyperTransport connect. The 4x4 will use AMD's new 1207-pin Socket F.

While the 4x4 is technically aimed at so-called high-end "enthusiast" users -- aka gamers -- AMD is making what appears to be a mainstream hedge in that at least one of the available 4x4 SKUs is supposed to come in at around $1,000.

Beyond the 4x4, AMD is working on a true quad-core desktop design code-named. A key feature is a new L3 cache that's shared by all four cores. It will also incorporate an enhanced implementation of AMD's HyperTransport interprocessor communications link. While the AMD desktop quad-cores will initially support DDR2 memory, they'll eventually migrate to even faster DDR3 RAM. [Update: Oct. 5. The initial version of this story reported that 'Barcelona' is the code name for AMD's planned quad-core desktop. That was incorrect. Barcelona is the code name for AMD's quad Opteron. There is currently no code name for AMD's quad desktop.]

Intel Desktop: Core 2 Quad

As is not atypical for its products, the nomenclature of Intel's desktop processor family requires some parsing if it's to be clearly understood. At IDF, Intel said it would give its desktop quad-cores the brand name "Core 2 Quad." However, the first four-CPU processor out of the chute won't have that moniker.

"The initial desktop version of the Quad microprocessor will be introduced as a member of our Xtreme family so it will be a Core 2 Xtreme; that's the brand name," Otellini said at IDF. "The product will ship in November. In Q1 of next year, as we bring on more capacity for these products and different price points, we'll bring [quad core] into the mainstream under the brand name of Core 2 Quad."

More specifically, that Core 2 Extreme will carry the alpha-numeric designation QX 6700. As with the current high-end, dual-core Core 2 Extreme, it'll be aimed largely at high-end gamers.

The Core 2 Extreme and its quad cousins show up on Intel's roadmap under the code name "Kentsfield." Intel has provided some early samples of the processor to enthusiast sites such as Tom's Hardware. Early reviews are highly positive. Judging from the Tom's review, it looks like the 6700 will be joined one rung down on the spec chart by a Core Quad 6400 part. This runs at 2.67 GHz and has a 4-MB L2 cache.

Beyond the initial Core 2 Quads, Intel has a slew of 45-nm processors in the works. Expect those to begin to hit the market in late 2007 or 2008.