Aug 23, 2007

Processor Roadmap : The multicore era is upon us

By Rich Brown and Michelle Thatcher (3/15/07, updated 06/11/2007)

Megahertz will take you only so far. Desktop processors topped the 1GHz mark in 2000, 2GHz in 2001, and 3GHz in 2002. Nearly five years later, we've yet to see a chip leave the factory clocked at 4GHz. Power demands and heat concerns meant that AMD and Intel couldn't simply keep ramping up clock speeds with each new CPU generation without running into design obstacles with desktops and especially with laptops.

Having come to the end of the megahertz rope, Intel and AMD looked to other methods for increasing processing power while maintaining or improving efficiency, the most significant of which was increasing the number of processing cores on a CPU. The multicore era began in spring 2005 with Intel's Pentium D 800 dual-core chips, and AMD soon followed with the Athlon 64 X2 chips. AMD dominated the initial round of head-to-head benchmarks, and Intel's subsequent Pentium D 900 series, released in the fall of 2005, did little to dampen the enthusiasm for AMD's X2 line.

AMD's run was short-lived as Intel sped back in the lead last year. Intel released the first dual-core mobile chip with Core Duo in January 2006, which brought about huge advances in laptop performance. Following that success, its Core 2 Duo launch in the summer of 2006--for both desktops (Conroe) and laptops (Merom)--can arguably be called the most successful product launch in the company's history. AMD is still reeling.

What sort of response is AMD readying to combat the runaway hit that is Core 2 Duo? What advances does Intel have in store later this year and next? How will each company expand on its nascent quad-core technology? We'll answer these questions and more as we explore Intel's and AMD's road maps, both the officially announced technologies around the corner and the rumors of those still a number of exits over the horizon.

Q2 2007

Not long after its Athlon 64 X2 processors toppled Intel's Pentium D chips, AMD found itself back in the familiar role of underdog when Intel moved to its 65-nanometer process and released the Core 2 Duo to universal praise last year. AMD introduced its first 65nm desktop chips at the end of 2006 with an update to its Athlon 64 X2 line. Throughout the rest of the first half of the year, AMD will continue to roll out 65nm Athlon 64 X2 parts, possibly with faster clock speeds (one of the benefits of reduced power consumption).

Dip your toes in Bearlake

Sometime this spring or early summer--the company has yet to pin an exact date on it--Intel will introduce a new chipset, which it's developing under the code name Bearlake. Intel did tell us the chipset will feature a 1,333MHz front-side bus and support for faster memory including DDR2-800 and DDR3-1333; new Core 2 Duo processors--Core 2 Duo E6650, E6750, and E6850--will be introduced at the same time that will support the faster front-side bus. The Bearlake chipset family will be divided into the P series, which will have a dedicated PCI Express graphics port, and the G series, which will feature an integrated graphics chip.

As with AMD's recently announced 690 chipset, the G35 chipset will come with HDCP support, making it easy for motherboard manufacturers to pair it with an HDMI video output. We also expect that the integrated graphics chip on the Intel G35 chipset (if not the G33 as well) will be DirectX 10 compatible, although we anticipate that gaming with an integrated graphics chip will remain a less-than-ideal experience.

In addition, Intel will expand its mainstream Core 2 Quad desktop chips by adding the Core 2 Quad Q6400 to its lineup in June. With new software coming out (such as the recent game Supreme Commander, tested by our stalwart colleagues at GameSpot) that demonstrates definite performance benefits from four processing cores, our hunch is this June release of a relatively lower-cost quad-core chip will begin to convince consumers that four cores really can help mainstream performance.

Movement on the mobile front

On May 9, Intel announced the new Centrino Duo and Centrino Pro mobile platforms, both code-named Santa Rosa. The platforms are built around a new generation of Core 2 Duo processors, including a high-end 2.4GHz Core 2 Duo T7700 version that was introduced to coincide with the platform launch. The platform's new chipset, code-named Crestline, includes an 800MHz front-side bus that has already brought modest performance gains and promises even more when 800MHz RAM hits the market later in 2007. Other elements of Santa Rosa include the Kedron wireless card, which features 802.11n (Draft N) interoperability but not the integrated options for 3G and WiMax connectivity we originally predicted.
Prior to the platform's official announcement, we were most excited about Robson caching technology, flash memory incorporated into the motherboard that can store a cache of commonly accessed information, such as the operating system and software, so you can boot the computer or launch applications without spinning the hard drive. Intel promises that Intel Turbo Memory (as Robson came to be officially named) can shorten boot times by as much as 20 percent, though our initial anecdotal tests have yet to reveal any added speed in laptops with the technology.

Mobile platforms

AMD also will see enhancements to its platform, code-named Kite, this quarter. Because AMD's platform is less strictly integrated than Intel's (the company describes it as an "open ecosystem," allowing laptop manufacturers to choose the wireless and graphics elements of the platform), the Kite refresh will be centered around a new processor family, code-named Hawk. The new processors will mark AMD's transition to a 65-nanometer manufacturing process for mobile CPUs and will support high-performance, 800MHz DDR2 memory. The company also promises that Kite will include a chipset with HDMI support as well as support for 802.11n (Draft N) wireless solutions. (AMD's next mobile platform will support the final 802.11n standard, which is expected to be ratified in April 2009.)

AMD presented a road map at an analyst day in December 2006 that also implied that Kite could make room for hybrid hard drives, which incorporate flash chips for fast data access.

Q3 2007

AMD goes native

AMD's most significant introduction this quarter, and arguably this year, will be its new quad-core Opteron server and workstation CPU, code-named Barcelona. This chip will be AMD's first native quad-core chip (that is, four cores on one die) of any kind, and it will also feature a brand new architecture and a 65nm manufacturing process. Barcelona will hopefully be an improvement over AMD's current and ill-conceived) Quad FX platform, which features a motherboard that can accept two physical dual-core processors.

One of the chief benefits of a native design will be a unified cache that can balance the processing load between various cores, including letting a single core or two cores use all of the cache, translating, in theory, to faster performance. Under the current scheme that pairs two dual-core chips to make an ad hoc four-core computer, each pair of cores can use only the cache that has been assigned to it. Naturally, the Opteron design will trickle down to desktop chips as well, so consider it a preview for what we hope will come out on the desktop side from AMD before the end of the year.

Intel readies high-end Bearlake chipset

Whether Intel's mainstream Bearlake chipsets come out in Q2 or Q3, Intel confirmed for us that it will be July before X38, the high-end member of the Bearlake family, hits the street. Aimed at gamers and performance enthusiasts, the X38 will feature support for 1,333MHz DDR3 memory, and it also will come with a pair of PCI Express 2.0 graphics slots, which double the data bandwidth of current PCI Express slots from 2.5Gbps to 5.0Gbps. That should translate to great benefits for 3D-graphics performance, especially with next-gen games played at high resolutions.

One thing we don't know is whether these dual-slot boards will support only ATI's Crossfire dual-graphics-card mode, as Intel's 975X motherboards do today, or if Intel and Nvidia will finally come together and add SLI support to an Intel chipset. Since Nvidia has a lucrative business with its own nForce SLI chipsets, we're not holding our breath. At any rate, the Intel X38 chipset should prove popular with gamers for enabling advances in memory and graphics performance.

Q4 2007

AMD focuses on quad cores for desktops

If everything goes according to plan with the quad-core Opteron, we have a feeling we'll see the first native quad-core Athlon processor for desktops before the end of 2007. We've heard rumors it may happen before the fourth quarter, but AMD won't verify any dates so we'll peg it for Q4 as a conservative estimate. We do know these new chips, code-named Agena, will use the Barcelona core, including HyperTransport 3.0. AMD's current Athlons use HyperTransport 2.0 to move data between different PC subsystems. HyperTransport 3.0 will work at faster data rates than the older version and should boost performance. Whether it's enough of a performance leap to help Agena and its dual core-equivalent (code-named Kuma) overtake Core 2 Duo remains the big question.

Introducing a native quad-core desktop part is important for AMD because the company's ad hoc Quad FX solution cannot keep pace with Intel's faster quad-core Core 2 Extreme or Core 2 Quad chips. Granted, Intel's Core 2 Quad chips aren't technically native quad core either, since their design involves two distinct L2 cache allotments for each pair of processing cores. But 65nm Core 2 Quad is much more power and heat efficient than current Quad FX, which requires two physical 90nm CPUs on a single motherboard, along with the accompanying cooling hardware.

Intel wins race to 45nm

Of course, Intel isn't letting up. The company has completed its 45-nanometer manufacturing process, and by the end of the year we expect to see the fruits of that labor. Similar to the release of the Core 2 Extreme X6800 before the rest of the Core 2 Duo line, Intel's highest-end 45nm desktop chips, code-named Wolfdale (dual-core) and Yorkfield (quad-core), will likely make their first appearance before the close of 2007, with the mainstream counterparts debuting in the beginning of 2008 (bet you a dollar we'll hear about them at next year's CES). Since for the most part these chips are more power-efficient Core 2 Duos, the Wolfdale/Yorkfield family likely won't introduce a major technological or performance leap. They're all 45nm chips, so Intel should be able to dial raw clock speeds and cache amounts past their current-gen Core 2 equivalents, but the most significant pure technology change will be a new set of multimedia and performance instructions, called SSE 4.0, which promises to improve data processing efficiency, and, hopefully, overall performance.

H1 2008

Socket to me

At this point, AMD should have its next-generation quad-core chips up and running, and it could even be wearing the desktop performance crown. If it's not, its next-gen motherboard socket, Socket AM3, due out in early 2008, might help it gain ground. Socket AM3 should allow AMD to catch Intel's Bearlake chipsets by adding support for 1,333MHz DDR3 memory, if not faster. From what we understand, the Socket AM3-compatible processors also will work with current Socket AM2 boards (although not vice versa), so you'll be able to extend the life of an AMD-based PC if you buy one this year.

Mobile platform advances

With the release of the new Puma platform in the first half of 2008, AMD will bring out a brand new mobile processor design, this one code-named Griffin. A key advancement with this CPU family will be the introduction of split power planes for granular power management. Each processor core will have its own power plane, with a third plane beneath the integrated memory controller and HyperTransport link. This design lets Puma chipsets control each plane independently, distributing and conserving power based on workload. AMD promises further power savings with "link power management," which applies the same dynamic scaling to HyperTransport link speeds. Finally, Puma will reportedly incorporate a hybrid-graphics solution, called Power Xpress, that promises to extend battery life by automatically switching from discrete to integrated graphics when the system is unplugged.

In addition to better power management, the chip-to-chip connections in Puma will meet the HyperTransport 3.0 standard, which could result in higher clock speeds and theoretically more efficient use of memory. Other technology updates on the platform include support for the final 802.11n specification and for DirectX 10, as well as the company's Universal Video Decoder technology, which provides dedicated video processing on the chipset.

Though Intel remains tight-lipped about its plans after the release of Santa Rosa, speculators agree that the first half--possibly even the first quarter--of 2008 is the most likely time frame for the introduction of mobile versions of Penryn, Intel's 45nm chip. Essentially a shrink of Core 2 Duo chips, Penryn includes a few enhancements; one such upgrade, SSE 4.0 instructions, will (according to Intel) improve the performance of multimedia applications. Another improvement will stem from Intel's switch to new materials for transistors, which should result in lower power consumption.

According to more than one report, Penryn will form the centerpiece of Intel's updated Centrino platform, code-named Montevina. The new platform will reportedly build upon its predecessor, incorporating a new chipset (Cantiga) with a 1,066MHz front-side bus as well as a new wireless module (Shiloh) that supports WiMax, the long-range wireless networking technology. Expected features for Montevina include Robson 2.0, which will take better advantage of Windows Vista's instant-on capabilities, and Intel Trusted Execution Technology, which protects data from malicious software.

2H 2008

Say hello to Nehalem

Where Penryn was Intel's move to increased power efficiency, Nehalem, set to debut in the latter half of 2008, will introduce a brand new architecture. This pattern of shrinking the die one year and then revamping the core architecture the next is how Intel chip development will proceed, at least under its currently stated release plan. Figure 2009 will feature more power-efficient, 32nm process Nehalem-equivalent chips(code-named Westmere), while 2010 will feature a new chip architecture design(code-named Gesher), and so on.

Intel's "tick-tock" cadence model

Intel has settled on an alternating schedule of shrinking the size of its chips with one release ("tick") while revamping the chips' architecture with the next release ("tock"). A tick-tock cycle will occur every two years.

Though little is known about Nehalem at this point, multiple sources contend Intel will drop the front-side bus altogether and link the CPU to other components on the board via Common System Interface, a next-generation interconnect technology designed to compete with AMD's HyperTransport.

AMD's projections are a bit murkier. We have a feeling we'll see at least a 45-nanometer Opteron before the end of 2008, if not a full-fledged 45nm, HyperTransport 3.0 Athlon desktop processor.

WiMax wager

In the realm of wild speculation, we suspect Intel will incorporate the Intel WiMax Connection 2300 into its mobile platform in 2008. The technology, which combines WiMax(802.16e-2005), 802.11n Wi-Fi, and high-speed downlink packet access (HSDPA) 3G capabilities on a single chipset, would allow even smaller laptops and UMPCs to incorporate multiple next-generation wireless connections. At this point, Intel will only commit to releasing WiMax Connection 2300 cards in early 2008, but our money says that if WiMax takes off, we'll see the chipset integrated into Intel's mobile platform before the end of the year.

2009 and beyond

AMD's acquisition of graphics chipmaker ATI should bear some collaborative fruit in early 2009, when the company is expected to debut the mobile Fusion product. Combining the CPU cores and GPU cores into one "accelerated processing unit," AMD anticipates that Fusion will provide a better graphics and media experience and (because only one chip is drawing power) extended battery life for laptop users.

Intel is characteristically mum on its plans for 2009, but CNET News.com reporter Tom Krazit noted earlier this year that the company was hiring developers for discrete graphics products. Krazit went on to hypothesize that the job posting, which described plans to focus initially on discrete graphics but then expand to work on CPU integration, signaled Intel's intent to develop an integrated GPU-CPU to compete with AMD's Fusion product.

Beyond traditional processors, our hunch is that the traditional desktop architecture is due for a revolution within the next few years. AMD's acquisition of graphics chip vendor ATI, AMD's Torrenza, and Intel's Geneseo and CSI initiatives, and Nvidia's CUDA all point to silicon performing new and different tasks and in combinations and arrangements we haven't really seen before. We don't expect we'll see much in the way of a tangible new computing model emerging this year, but what we envision when we think of a computer could be in for a dramatic change sooner than you think.

Finally, if you're wondering what's next in the race for multicore supremacy, both AMD and Intel have motherboards out that will accommodate two quad-core CPUs, which lets you build a string-and-baling wire eight-core computer. CNET Labs pulled the same trick on the Mac Pro a few months ago. We found no details, official or otherwise, regarding native eight-core chips in our research for this story, but it's not hard to imagine that eight-core processing might make its way to the desktop within the next few years. It could be that Intel's 45nm Nehalem is heat efficient enough to make an eight-core (octo-core?) CPU possible, so perhaps we'll see one as soon as 2008. We have a feeling Intel will be the first to make the leap, since AMD is still playing catch-up in terms of moving to 65nm and introducing quad core. Whether the software will be ready to benefit from eight-core chips when they inevitably arrive is another question.