Core Microarchitecture
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Contents |
Introduction
Intel's Core Microarchitecture is the basis for a series of CPUs that will become the mainstay of their lineup in the coming year. Designed as a replacement for the aging Netburst architecture, Core provides Intel with a new foundation to move forward. Based largely on the successful Pentium M microprocessors, it places a deep focus on efficiency in every aspect of its design.
Major Features
Multi-Core
While some single-core variants are expected in 2007, all of the current Core-based models are dual-core processors. The Core architecture was designed for multi-core implementations from the start, and will continue to embrace the advantages of this technology. Intel already has plans for quad-core models by the end of the year, and will go beyond that in the future.
64-bit Computing (EM64T)
While EM64T support was widespread in the last round of Netburst-based processors, the Pentium M and Core Duo processors did not support it. The new Core architecture makes it a standard feature across the line, so from this point forward all new processors will contain full 64-bit support. Combined with the upcoming release of Windows Vista, this should help to usher 64-bit computing into the mainstream.
Advanced Digital Media Boost
As digital media is becoming an increasingly important component in modern computing, these new processors contain a number of optimizations in their vector processing units. These new processors can now perform many of these complex operations in a single clock cycle, potentially doubling their throughput versus previous designs.
Intelligent Power Capability
As reducing power consumption is a high priority for this new architecture, these chips contain a number of new technologies. Aside from the ability to throttle the clock speed of each of the cores independently, these chips can dynamically shut down unneeded units.
Advanced Smart Cache
Unlike conventional dual-core designs, these microprocessors share a single large bank of L2 cache. As both cores can access the entire capacity of the cache, they can make more efficient use of the available memory. Additionally, as a core can directly access data that was cached by the other core this strategy can significantly reduce front-side bus traffic.
Smart Memory Access
In order to help offset the advantage that AMD's onboard memory controllers offer, these processors offer a host of technologies to optimize the use of memory bandwidth. These systems are designed to look ahead and intelligently plan main memory accesses.
Virtualization Technology
Formerly known as Vanderpool, this system provides hardware-level support for virtualization. This allows users to run multiple operating systems in parallel with one another. While not typically a major feature for photographers, it can be a powerful tool for a number of different tasks.
Execute Disable Bit
To help improve the security of modern computers, Intel is incorporating an execute disable bit in their newer microprocessors. This restricts execution of code to certain portions of main memory and helps to prevent malicious code from being executed.
Clock Rates
While high clock speeds can provide improvements in performance, they have a number of negative side effects that go along with them. Primarily, processors running at higher clock rates typically consume much more power and, as a result, produce much more heat. With the later models in the Netburst line outputting upwards of 135W of heat, this became a significant impediment to future progress with those processors.
The Core microarchitecture was designed specifically to address this problem. Instead of being designed to allow extremely high clock rates, these processors were designed to maximize efficiency and do more during each cycle. While this has made it more difficult to reach the clock rates Netburst users may be used to, it is largely responsible for the significant decrease in power consumption (in some cases as much as half).
The Netburst chips, on the other hand, were designed specifically to maximize clock rates and sacrificed efficiency to achieve that goal. As such, when comparing the two product lines it is important to realize that, despite the much lower clock rates, the new Core-based processors will almost always be faster than their predecessors. While clock rates are an important determinant of performance within a specific architecture, they are not necessarily a good metric when comparing two different architectures.
Performance per Watt
One of the major marketing angles that Intel is focusing on is the concept of performance per watt. While the concept of power consumption was never a major factor in the past, it has grown increasingly important over the last couple of years. As such, Intel has focused much of their engineering efforts on providing increased performance while significantly decreasing power consumption and heat output.
The Core architecture is a key pillar of this new push, as it provides improvements in performance over its predecessor while cutting power consumption and heat output in half. While the direct benefits are most apparent on battery powered devices like laptops, this also provides benefits for other users. Reduced heat output means simpler cooling systems, which in turn means less noise and increased durability. Additionally, with the increase in global energy prices this can provide significant benefits for organizations with large numbers of computers on hand.
Variants
The initial release of this architecture was focused on three key products, code named Merom, Conroe and Woodcrest. While based on the same underlying design, each of these chips is optimized for a different target market. The use of a unified foundation across these lines helps Intel to move them forward in lock step, while still providing the unique features required by each of these markets.
Merom (Core 2 Duo T5xxx/T7xxx)
These processors are designed with power consumption and heat output as key considerations and, as such, are primarily intended for portable computers. Designed with a target TDP of 35W or less, these processors will provide extremely long battery lives and require only modest cooling. As such, these processors will become part of Intel's Centrino brand replacing the current Core Duo and Pentium M lines.
In addition, these processors will be drop-in replacements for existing Core Duo motherboards. As such, manufacturers will be able to add support for these processors with minimal effort so initial costs should be kept down. Further, it may be possible for end users to upgrade some Core Duo and Core Solo-based computers to make use of these processors.
Conroe (Core 2 Duo E6xxx)
Designed for use in larger desktop computers, these processors will focus primarily on maximum performance. These chips will provide faster front-side busses, higher clock rates and a number of other features. In order to offer these features, however, these processors will have a higher TDP of approximately 65W.
These chips are designed to replace the Pentium 4 and Pentium D processor lines, based on the ageing Netburst architecture. The various advances provided by this architecture allow these new processors to provide significant improvements in performance, while using only a fraction of the energy.
While these processors can use the same chipsets (965X/975X) and socket (LGA775) as the earlier Netburst chips, they have some unique power requirements that will typically require motherboard manufacturers to make some minor modifications. As such, most current machines will require a new motherboard to support these processors (although the new motherboards will support the Netburst chips as well).
Core 2 Extreme
The top-of-the-line processor in the Conroe line, Core 2 Extreme provides a number of enthusiast related features as well as a higher clock rate than the other Conroe processors. Further, these processors will have a number of features that make them easier for users to overclock if desired. To provide these capabilities, however, these processors will run with TDPs in the 75-85W range.
Allendale
Allendale processors are variants with only 2MB (vs. 4MB) of L2 cache but are otherwise identical to the Conroe chips. This will allow these processors to be sold at a lower pricepoint to cater to different markets. At the current stage Netburst-based chips will also occupy this market, however as time passes the Allendale line will eventually supplant them fully.
Woodcrest (Xeon 51xx)
Aimed at servers and workstations, the Woodcrest line is designed to address the needs of the high-end of the market. Unlike Merom and Conroe, Woodcrest-based chips can be used in multiple-processor configurations. While considerably more expensive than their desktop brethren, these processors allow manufacturers to build extremely high performance computers.
FB-DIMM Memory
In addition, Woodcrest processors are designed to be used with FB-DIMM memory technology. Unlike the direct connections used by conventional DDR2 memory, FB-DIMMs use a high-speed serial link between the memory modules and chipset. This allows higher memory bandwidth, enhanced stability and much simpler interconnects.
Most importantly, however, FB-DIMMs are hardware-agnostic - that is, memory controllers are not bound to a single technology. When new memory technology such as DDR3 comes to market, this will allow it to be installed in existing machines without issue.
The downside, however, is that FB-DIMM implementations create additional latency to each memory request. While the additional memory bandwidth provided by this technology will often offset this disadvantage, some tasks are sensitive to latency and may be negatively affected.
Product Line
The following table describes the various models that will make use of this new architecture. Note that this lineup will grow over the next few months, however at this stage in the game the following models have been published:
| Model | Type | Clock Speed | L2 Cache | FSB | TDP | Cores | SMP | Available |
|---|---|---|---|---|---|---|---|---|
| Core 2 Duo E6300 | Allendale | 1,866MHz | 2MB | 1,066MHz* | 65W | 2 | N | 27/07/2006 |
| Core 2 Duo E6400 | Allendale | 2,133MHz | 2MB | 1,066MHz* | 65W | 2 | N | 27/07/2006 |
| Core 2 Duo E6600 | Conroe | 2,400MHz | 4MB | 1,066MHz* | 65W | 2 | N | 27/07/2006 |
| Core 2 Duo E6700 | Conroe | 2,666MHz | 4MB | 1,066MHz* | 65W | 2 | N | 27/07/2006 |
| Core 2 Extreme X6800 | Conroe XE | 2,933MHz | 4MB | 1,066MHz* | 75W | 2 | N | 27/07/2006 |
| Xeon E5110 | Woodcrest | 1,600MHz | 4MB | 1,066MHz* | 65W | 2 | Y(2) | Y |
| Xeon E5120 | Woodcrest | 1,870MHz | 4MB | 1,066MHz* | 65W | 2 | Y(2) | Y |
| Xeon E5130 | Woodcrest | 2,000MHz | 4MB | 1,333MHz* | 65W | 2 | Y(2) | Y |
| Xeon E5140 | Woodcrest | 2,330MHz | 4MB | 1,333MHz* | 65W | 2 | Y(2) | Y |
| Xeon E5148LV | Woodcrest | 2,330MHz | 4MB | 1,333MHz* | 40W | 2 | Y(2) | Q3 2006 |
| Xeon E5150 | Woodcrest | 2,660MHz | 4MB | 1,333MHz* | 65W | 2 | Y(2) | Y |
| Xeon E5160 | Woodcrest | 3,000MHz | 4MB | 1,333MHz* | 80W | 2 | Y(2) | Y |
See Also
- Microprocessors - Article describing various topics surounding microprocessors in general.
- Core 2 Duo/Solo - Article covering the specific details of the Core 2 Duo/Solo family of microprocessors.
- AMD K8L - AMD's upcomming architecture designed to compete with this new technology.
External Links
- Intel's Whitepapers - Intel's technical documents covering the new Core microarchitecture. Provides detailed descriptions of the new features provided in this new line of processors.
- Core 2 Family - Intel's marketing website covering the Merom and Conroe lines of processors.
