Moscow State University

The Department of Computational Mathematics and Cybernetics

Intel Core i7

Timofeev Kirill
Group 205

Moscow 2010

Introduction

Intel Core i7 is an Intel brand name for several families of desktop and laptop 64-bit x86-64 processors using the Nehalem, Westmere, and Sandy Bridge microarchitectures and manufactured in Costa Rica and Malaysia. The Core i7 brand is targeted at the business and high-end consumer markets for both desktop and laptop computers, and is distinguished from the Core i3 (entry-level consumer), Core i5 (mainstream consumer) and Xeon (server) brands.
In each of the first three microarchitecture generations of the brand, Core i7 has family members using two distinct system-level architectures, and therefore two distinct sockets. In each generation, the highest-performing Core i7 processors use the same socket and QPI-based architecture as the low-end Xeon processors of that generation, while lower-performing Core i7 processors use the same socket and PCIe/DMI/FDI architecture as the Core i5.
"Core i7" is a successor to the Intel Core 2 brand. The Core i7 identifier was first applied to the initial family of processors codenamed Bloomfield introduced in 2008. In 2009 the name was applied to Lynnfield and Clarksfield models. Prior to 2010, all models were quad-core processors. In 2010, the name was applied to dual-core Arrandale models, and the Gulftown Core i7-980X Extreme processor which has six hyperthreaded cores. In January 2011, Intel released a line of Sandy Bridge based chips under the Core i7 brand.

Microarchitectures
Nehalem
Nehalem is the codename for an Intel processor microarchitecture, successor to the Core microarchitecture. The first processor released with the Nehalem architecture was the desktop Core i7, which was released in November 2008. It was followed by several Xeon processors and by the i3 and i5.Mobile Nehalem-based processors were introduced in September 2009. The first computer to use Nehalem-based Xeon processors was the Apple Mac Pro workstation announced on March 3, 2009. Nehalem-based Xeon EX processors for larger servers were originally expected in Q4 2009, However, they were released in April 2010.
Initial Nehalem processors use the same 45 nm manufacturing methods as Penryn. A working system with two Nehalem processors was shown at Intel Developer Forum Fall 2007.
Technology
    * Two, four, six cores
    * 45 nm manufacturing process at initial release (with 32 nm variants following)
    * Integrated memory controller supporting two or three memory channels of DDR3 SDRAM or four FB-DIMM2 channels
    * Integrated graphics processor (IGP) located off-die, but in the same CPU package for Westmere.
    * A new point-to-point processor interconnect, the Intel QuickPath Interconnect, in high-end models, replacing the legacy front side bus
    * Integration of PCI Express and Direct Media Interface into the processor in mid-range models, replacing the northbridge
    * Hyper-threading has been reintroduced.
    * Native (monolithic, i.e. all processor cores on a single die) quad- and octal-core processors
    * 64 KB L1 cache/core (32 KB L1 Data + 32 KB L1 Instruction) and 256 KB L2 cache/core.
    * 4–12 MB L3 cache shared by all cores
    * 33% more in-flight micro-operations than Conroe[12]
    * Second-level branch predictor and second-level translation lookaside buffer

 Performance and power improvements
It has been reported that Nehalem has a focus on performance, which accounts for the increased core size. Compared to Penryn, Nehalem has:
    * 1.1× to 1.25× the single-threaded performance or 1.2× to 2× the multithreaded performance at the same power level
    * 30% lower power usage for the same performance
    * According to a preview from AnandTech "expect a 20–30% overall advantage over Penryn with a 10% increase in power usage."[14]
    * Per Core, clock-for-clock, Nehalem provides a 15–20% increase in performance compared to Penryn.
PC Watch found that a Nehalem "Gainestown" processor has 1.6× the integer performance and 2.4× the floating-point performance of a 3.0 GHz Xeon X5365 "Clovertown" quad-core processor.A 2.93 GHz Nehalem "Bloomfield" system has been used to run a 3DMark Vantage benchmark and gave a CPU score of 17,966. The 2.66 GHz variant scores 16,294. A 2.4 GHz Core 2 Duo E6600 scores 4,300.AnandTech tested the Intel QuickPath Interconnect ("QPI", 4.8 GT/s version) and found the copy bandwidth using triple-channel 1066 MHz DDR3 was 12.0 GB/s. A 3.0 GHz Core 2 Quad system using dual-channel 1066 MHz DDR3 achieved 6.9 GB/s.
The Nehalem processors are the first to incorporate the SSE 4.2 SIMD instructions, adding 7 new instructions to the SSE 4.1 set available in the Core 2 series.The Nehalem architecture also significantly reduces atomic operation latency; cutting it to 50% in an attempt to eliminate atomic overhead .

Westmere
Westmere (formerly Nehalem-C) is the name given to the 32 nm die shrink of Nehalem. The first Westmere-based processors were launched on January 7, 2010 and branded as members of the Core i3, Core i5, and dual-core mobile Core i7 families.
Westmere's features and improvements from Nehalem have been reported as follows:
    * Native six-core processors.
    * A new set of instructions that gives over 3x the encryption and decryption rate of Advanced Encryption Standard (AES) processes compared to before.
     		o Delivers seven new instructions (AES instruction set or AES-NI) that will be used by the AES algorithm. Also an instruction called PCLMULQDQ (see CLMUL instruction set) that will perform carry-less multiplication for use in cryptography. These instructions will allow the processor to perform hardware-accelerated encryption, not only resulting in faster execution but also protecting against software targeted attacks.
     		o AES-NI may be included in the integrated graphics of Westmere.
    * Integrated graphics, built into the processor.
    * Improved virtualization latency.
    * New virtualization capability: "VMX Unrestricted mode support," which allows 16-bit guests to run (real mode and big real mode).
    * Support for "Huge Pages" of 1GB in size.

Sandy Bridge
Sandy Bridge is the second generation Intel Core i7 series processor, and is based on microarchitecture also named "Sandy Bridge". It was released on January 9, 2011 at the end of CES 2011.
Sandy Bridge, formerly Gesher, is the codename for the processor microarchitecture developed by Intel as the successor to Nehalem. Based on the 32 nm process, development began in 2005 at Intel's Israel Development Center (IDC) in Haifa.
On January 31, 2011, Intel announced that it had found a design flaw in its Cougar Point 6 series chipset, that accompanies the LGA 1155 socket, affecting SATA-II ports (number 2 to 5) and a recall was issued. It announced that replacements will be out to motherboard manufacturers by the end of February 2011, and has shipped the revised chipset (B3) since February 14, 2011. Most mainstream boards should meet demand by the beginning of April 2011.

 Performance
Sandy Bridge processors are up to 17% faster clock-for-clock compared to Nehalem processors. Its integrated graphics provides around twice the performance of Westmere's, which is 12EUs.

Processor cores
The initial Core i7 processors released were codenamed Bloomfield, branded as Core i7-9xx along with their Xeon 3500-series counterparts. As of 2009, they are Intel's high-end Desktop processors, sharing the Socket 1366 platform with the single and dual-processor server processors.

Bloomfield (microprocessor)
Bloomfield is the code name for Intel high-end desktop processors sold as Core i7-9xx and single-processor servers sold as Xeon 35xx., in almost identical configurations, replacing the earlier Yorkfield processors. The Bloomfield core is closely related to the dual-processor Gainestown, which has the same CPUID value of 0106Ax (family 6, model 26) and which uses the same socket. Bloomfield uses a different socket than the later Lynnfield and Clarksfield processors based on the same 45 nm Nehalem microarchitecture, even though some of these share the same Intel Core i7 brand.
Bloomfield has many new features that represent significant changes from Yorkfield:
    * The new LGA 1366 socket is incompatible with earlier processors.
    * On-die memory controller: the memory is directly connected to the processor. It is called the uncore part and runs at a different clock (uncore clock) than the execution cores.
          o Three channel memory: each channel can support up to two DDR3 DIMMs. Motherboards for Bloomfield generally have three, four (2, 1, 1), or six DIMM slots.
          o Support for DDR3 memory only.
    * The front side bus has been replaced by the Intel QuickPath Interconnect interface. Motherboards must use a chipset that supports QuickPath Interconnect.
    * The following caches:
          o 32 kB L1 instruction and 32 kB L1 data cache per core
          o 256 kB L2 cache (combined instruction and data) per core
          o 8 MB L3 (combined instruction and data) "inclusive", shared by all cores
    * Single-die device: all four cores, the memory controller, and all cache are on a single die, instead of a Multi-chip module of two dual-core dies as in Yorkfield
    * "Turbo Boost" technology allows all active cores to intelligently clock themselves up in steps of 133 MHz over the design clock rate as long as the CPU's predetermined thermal and electrical requirements are still met.
    * Re-implemented Hyper-threading. Hyperthreading was introduced in the older NetBurst microarchitecture, but omitted from the subsequent Core, which was a descendant of the Pentium III family. With hyperthreading enabled, each of the four physical cores can process up to two threads simultaneously, so the processor appears to the OS as eight logical CPUs.
    * Only one QuickPath interface: not intended for multi-processor motherboards.
    * 45 nm process technology.
    * 731 million transistors.
    * 263 mm2 die size.
    * Sophisticated power management can place an unused core in a zero-power mode.
    * Support for SSE4.2 & SSE4.1 instruction sets.

Performance
    * The Inquirer managed to get a 965 engineering sample to a core clock rate of up to 4 GHz with fan cooling and Turbo Boost.
    * IT OC Taiwan overclocked an engineering sample of the 965, to 4.20 GHz with a QPI rate of 200 MHz and a multiplier value of 21.0. A vCore setting of 1.72 V was used, which is far higher than the stock voltage of 1.25V and could have led to damaging the CPU or motherboard.
    * A Core i7 940 system running at stock clock rates has obtained a 3DMark Vantage benchmark CPU score of 17,966. A Core i7 920 system scored 16,294 running at stock clock rates. An Intel Core 2 Extreme QX9770, a very expensive member of the previous generation of Intel processors (costing over four times the price of the 920 at its launch), scored 13,182 also running at stock clock rates.
    * AnandTech tested the Intel QuickPath Interconnect (4.8 GT/s version) and found the copy bandwidth using triple-channel 1,066 MHz DDR3 was 12.0 GB/s. A 3.0 GHz Core 2 Quad system using dual-channel 1066 MHz DDR3 achieved 6.9 GB/s.
    * Maximum PC has discovered that Intel has unlocked the QPI clock and memory multipliers on retail 920s and 940s. This is allegedly due to consumer feedback.
        * The Intel Core i7-975 Extreme Edition was considered the world's fastest desktop processor (until the i7-980x) by a review from Hot Hardware. It runs at a clock rate of 3.33 GHz with Turbo Boost clock rates running the processor up 3.46 GHz with all four cores put at work and 3.6 GHz with a single core at work. The processor was overclocked to 4.1 GHz while keeping a 50 °C (122 °F) core temperature with the stock cooling unit.

Drawbacks
The Core i7 Bloomfield does not support error-correcting memory.Some motherboards with an LGA 1366 socket support both Core i7 and the Xeon 35xx and 55xx series processors, and advertise support for ECC memory. However ECC functionality is only available if a Xeon is installed, not if a Core i7 is installed..

Lynnfield (microprocessor)
Lynnfield is the second processor sold under the Core i7 brand, while at the same time being sold as Core i5. Unlike Bloomfield, it does not have a QPI interface but directly connects to a southbridge using a 2.5 GT/s Direct Media Interface and to other devices using PCI Express links in its Socket 1156. Core i7 processors based on Lynnfield have Hyper-Threading, which is disabled in Lynnfield-based Core i5 processors.
Lynnfield is the code name for a quad-core processor from Intel released in September 2009. It is sold in varying configurations as Core i5-7xx, Core i7-8xx or Xeon X34xx. Lynnfield uses the Nehalem microarchitecture and replaces the earlier Penryn based Yorkfield processor, using the same 45 nm  process technology, but a new memory and bus interface. The product code for Lynnfield is 80605, its CPUID value identifies it as family 6, model 30 (0106Ex).
Lynnfield is related to the earlier Bloomfield and Gainestown microprocessors, which are used in server and high-end desktop systems. The main difference between the two is Lynnfield's use of the LGA 1156 processor socket as opposed to the LGA 1366 used in the others. LGA 1156 processors include Direct Media Interface and PCI Express links, which Intel has previously connected to the processor with a dedicated northbridge chip, called the memory controller hub or I/O hub.
The mobile version of Lynnfield is Clarksfield.

Clarksfield (microprocessor)
Clarksfield is the mobile version of Lynnfield and available under the Core i7 Mobile brand, as part of the Calpella platform. It was released at the Intel Developer Forum on September 23, 2009.
Clarksfield is the code name for an Intel processor, initially sold as mobile Intel Core i7. It is closely related to the desktop Lynnfield processor, both use quad-core dies based on the 45 nm Nehalem microarchitecture and have integrated PCI Express and DMI links.
The predecessor of Clarksfield, Penryn-QC was a multi-chip module with two dual-core Penryn dies based on Penryn microarchitecture, a shrink of Core microarchitecture. The name of the direct successor of Clarksfield has not been announced. Arrandale is a later mobile processor but opens a new line of mid-range dual-core processors with integrated graphics.
At the time of its release at the Intel Developer Forum on September 23, 2009, Clarksfield processors were significantly faster than any other laptop processor, including the Core 2 Extreme QX9300. The initial laptop manufacturers shipping products based on Clarksfield processors include MSI, Dell/Alienware, Hewlett-Packard, Toshiba and Asustek.

Brand names
As of September 2009, all Clarksfield processors are marketed as Core i7, in three product lines differing in thermal design power and the amount of third-level cache that is enabled. See the respective lists for details about each model.
Arrandale (microprocessor)
The second mobile Core i7 processor family is Arrandale, sold as the Core i7-6xx processors and featuring an integrated graphics processing unit but only two processor cores, half of Clarksfield. Clarkdale, the desktop version of Arrandale, will not be sold as Core i7, but only as Core i3 and Core i5. All support Intel's Hyper Threading (HT).
Arrandale is the code name for a mobile Intel processor, sold as mobile Intel Core i3, i5 and i7 as well as Celeron and Pentium. It is closely related to the desktop Clarkdale processor; both use dual-core dies based on the 32 nm Westmere shrink of the Nehalem microarchitecture and have integrated Graphics as well as PCI Express and DMI links.
Arrandale is the successor of the 45 nm Core microarchitecture based Penryn processor that is used in the many mobile Intel Core 2, Celeron and Pentium Dual-Core processors. While Penryn typically used both a north bridge and a south bridge, Arrandale already contains the major north bridge components, which are the memory controller, PCI Express for external graphics, integrated graphics and the DMI connector, making it possible to build more compact systems without a separate northbridge or discrete graphics as Lynnfield. The Arrandale processor package contains two dies, the actual 32 nm processor with the I/O connections and the 45 nm graphics controller with the memory interface.
Arrandale was released on 7 January 2010, during CES 2010.

Brand names
Arrandale processors are sold under the Celeron, Pentium, Intel Core i3, Intel Core i5 and Intel Core i7 brand names, with only the Core i7 models using the full L3 cache and all features. Processors ending in E instead of M are embedded versions with support for PCIe bifurcation and ECC memory, while the regular mobile versions only support a single PCIe port and non-ECC memory. The Celeron versions of Arrandale have the smallest L3 cache of just 2 MB.

Gulftown
Gulftown is the die shrink of the original Core i7, featuring 6 cores, 32 nm process, Hyper-Threading (for a total of 12 logical threads), 12 MB of cache, Turbo Boost and Intel QuickPath connection bus.
Gulftown or Westmere-EP is the codename of a six-core hyperthreaded Intel processor able to run up to 12 threads in parallel. It is based on Westmere microarchitecture, the 32 nm shrink of Nehalem. Originally rumored to be called the Intel Core i9, it is sold as an Intel Core i7. The first release was the Core i7 980X in the first quarter of 2010, while its server versions are the Xeon 3600- and 5600-series. The i7-970 has recently been released, with a 24x locked multiplier.
First figures indicate that at equivalent clock rates, depending on the software, it has up to 50% higher performance than the identically clocked quad core Bloomfield Core i7 975. However, consumer software that utilizes 6 real and 6 virtual cores is still quite rare, and not every multithreaded program is able to take advantage of this many cores. Despite having 50% more transistors, the CPU strongly benefits from the 32-nm process, drawing the same or even less power (depending on the operating system) than its Bloomfield predecessors with merely four cores. The thermal design power (TDP) of all planned models is stated to be 130 watts.
Gulftown is the first six-core dual-socket processor from Intel, following the quad-core Bloomfield and Gainestown (a.k.a. Nehalem-EP) processors using the same LGA 1366 package, while the earlier Dunnington six-core processor is a Socket 604 based multi-socket processor. The CPUID extended model number is 44 (2Ch) and two product codes are used, 80613 for the UP desktop/server models and 80614 for the Xeon 5600-series DP server models. In some models, only four of the six cores are enabled.

Conclusion

Now Intel Core i7 is one of the most popular types of processors, being used in possibly all types of computers. The development of these processors is continuing and soon may be we will see the third generation of this processors or Intel Core i7 will 'dead' and companies will develop other processors' types, which are more convenient for market.

References

1.  http://en.wikipedia.org/wiki/Intel_Core_i7
2.  http://en.wikipedia.org/wiki/Bloomfield_%28microprocessor%29
3.  http://en.wikipedia.org/wiki/Lynnfield_%28microprocessor%29
4.  http://en.wikipedia.org/wiki/Clarksfield_%28microprocessor%29
5.  http://en.wikipedia.org/wiki/Arrandale_%28microprocessor%29
6.  http://en.wikipedia.org/wiki/Gulftown_%28microprocessor%29
7.  http://en.wikipedia.org/wiki/Sandy_Bridge
8.  http://www.intel.com/products/processor/corei7/index.htm
9.  http://www.intel.com/products/processor/corei7EE/index.htm
10. http://en.wikipedia.org/wiki/Nehalem_%28microarchitecture%29