1. Intel Core i5 Processors
Architecture
A perspective view inside
SAU/MSc (CS)

2. Main Topics
• A brief introduction
• Intel processor architecture
• Multi Core architecture
• Performance evaluation
• Core I5 specification
• New features

3. Processor
• Is the portion of a computer system that carries out the
instructions of a computer program, and is the primary element
carrying out the computer's functions. This term has been in use
in the computer industry at least since the early 1960s .
• The form, design and implementation of CPUs have changed
dramatically since the earliest examples, but their fundamental
operation remains much the same.

4. The Process
• Process is a program in execution .A process is more than the
program code which is known sometimes as a text section.
• It also includes the current activity, as represented by the value of
the program counter & the contents of the processor's registers.
• Process generally includes the process stack, which contains
temporary data (such as method parameters ,return addresses,
local variables),and data section, which contains global variables.

5. Intel Processors Roadmap

6. Intel processors architecture
• In this presentation we focus on four recently released
microprocessors by Intel :
– NetBurst (microarchitecture)
– Core (microarchitecture)
– Nelahem (microarchitecture)
– Sandy Bridge (microarchitecture)

7. NetBurst (microarchitecture)
• The NetBurst microarchitecture, called P68 inside Intel, was
the successor to the P6 microarchitecture in the x86 family
of CPUs made by Intel.
• The first CPU to use this architecture was
the Willamette core of the Pentium 4 and the first of
the Pentium 4 CPUs
• All subsequent Pentium 4 and Pentium D variants have also
been based on NetBurst.

8. NetBurst cont…
• The NetBurst microarchitecture includes features such as :
• Front-Side Bus
• Hyper Pipelined Technology
– This is the name given to the 20-stage instruction pipeline within the
Willamette core
• Rapid Execution Engine
– With this technology, the two ALUs in the core of the CPU are
double-pumped
• Execution Trace Cache
– It stores decoded micro-operations, so that when executing a new
instruction, instead of fetching and decoding the instruction again,
the CPU directly accesses the decoded micro-ops from the trace
cache, thereby saving considerable time.

9. Multi-Core (microarchitecture)
• A multi-core processor is a single computing component with two
or more independent actual central processing units (called
"cores"), which are the units that read and execute program
instructions.
• The instructions are ordinary CPU instructions such as add, move
data, and branch, but the multiple cores can run multiple
instructions at the same time, increasing overall speed for
programs amenable to parallel computing.
• Manufacturers typically integrate the cores onto a
single integrated circuit die (known as a chip multiprocessor or
CMP), or onto multiple dies in a single chip package.

10. Single Core Architecture

11. Multi Core Architecture
• This talk is about a new trend in computer architecture:
Replicate multiple processor cores on a single die.

12. Multi-core CPU chip
• The cores fit on a single processor socket
• Also called CMP (Chip Multi-Processor)
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13. The cores run in parallel
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14. Within each core, threads are time-sliced
(just like on a uniprocessor)
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15. Concept of Core

16. Interaction with the Operating System
• OS perceives each core as a separate processor
• OS scheduler maps threads/processes
to different cores
• Most major OS support multi-core today:
Windows, Linux, Mac OS X, …

17. Why multi-core ?
• Difficult to make single-core clock frequencies even
higher
• Deeply pipelined circuits:
– heat problems
– speed of light problems
– difficult design and verification
– large design teams necessary
– server farms need expensive
air-conditioning
• Many new applications are multithreaded
• General trend in computer architecture (shift towards
more parallelism)

18. Nehalem (microcomputer)
• Nehalem is the codename for an Intel processor
microarchitecture, successor to the Core microarchitecture.
• Nehalem processors use the 45 nm process.
• The first processor released with the Nehalem architecture
was the desktop Core i7, which was released in November
2008.
• Nehalem, a recycled codename, refers to a completely
different architecture from Netburst

19. Nehalem cont…
• Focus on performance
• Utilize higher clock speeds and are more energy-efficient
• Hyper-threading reintroduced.
• 4–12 MB L3 cache
• Native (all processor cores on a single die) quad- and octa-core
processors
• Intel QuickPath Interconnect in high-end models replacing the
legacy front side bus
• Integrated memory controller supporting two or three memory
channels of DDR3 SDRAM
• 2nd generation Intel Virtualization Technology which introduced
Extended Page Table support

20. Sandy Bridge (micro Computer)
• Sandy Bridge is the codename for a microarchitecture developed
by Intel beginning in 2005 for central processing units in
computers to replace the Nehalem microarchitecture. Intel
demonstrated a Sandy Bridge processor in 2009, and released
first products based on the architecture in January 2011 under
the Core brand.

21. Sandy Bridge cont…
• Upgraded features from Nehalem include:
– Shared L3 cache includes the processor graphics
– 64-byte cache line size
– Two load/store operations per CPU cycle for each memory channel
– Decoded micro-operation cache and enlarged, optimized branch
predictor
– Improved performance for transcendental mathematics, AES
encryption (AES instruction set), and SHA-1 hashing
– 256-bit/cycle ring bus interconnect between cores, graphics, cache
and System Agent Domain
– Advanced Vector Extensions (AVX) 256-bit instruction set with wider
vectors, new extensible syntax and rich functionality
– Intel Quick Sync Video, hardware support for video encoding and
decoding
– Up to 8 physical cores or 16 logical cores through Hyper-threading

22. Family of Processors
This new family of processors consists of three classes
– core i3, core i5 and core i7.
• The Intel core i3 series has been made to cater to the entry
level desktop and laptop computer market.
• The core i5 series is aimed at the mid level computing
segment.
• The core i7 series is stuffed with high performance
processors that can serve the high end market.
• Every series of processors comes with a lot of variety, in
terms of processing speed and features.

23. Our Focus on Core i5 Processors
• Intel has just announced their latest lineup of Core i5
processors.
• Sandy Bridge, as the new architecture is called by engineers
is Intel's new microarchitecture, following Nehalem.
• The new processors are produced on Intel's 32 nm
production process which has reached maturity over the last
few months.

24. Core i5 Quad-Core Structure

25. Core i5 processor
• The core i5 line consists of three separate series of processors
with
i) DualCore Core i5 Processors
ii) QuadCore Core i5 Processors
• The DualCore Core i5 , as well as quad cores come with 4 threads
each.
• The clocking frequency ranging from 2.933 GHz to 3.2 GHz
• 4 MB to 8 MB L3 cache
• Direct media interface
• Intel HD graphics
• Intel smart cache technology
• Hyper-threading enabled
• i5 chips are faster than the i3 chips

26. The main key points for corei5 to
comparison
• Core Confusion
• Give Me the Cache
• A Word on Turbo Boost
• Hyper-Threading
• Integrated Graphics

27. Core Confusion
• Get faster CPU performance from Core i7 parts than
Core i5
• The majority of desktop Core i7 CPUs are quad-core
processors, while many mobile Core i5 processors are dual-
core.
• There are mobile dual-core Core i7 processors, and likewise
several desktop quad-core Core i5 processors.
• Rare six-core Core i7, which are usually found with the
desktop-only Extreme Edition top-of-the-line models.
• To get better performance in each generation, buy a
processor with a higher model number

28. Cache Memory
• In addition to generally faster base clock speeds, Core i5
processors have larger cache (on-board memory).
• help the processor deal with repetitive tasks faster.
• If you're editing and calculating spreadsheets, your CPU
shouldn't have to reload the framework the numbers sit in.
This info will sit in the cache so that when you change a
number the calculations are almost instantaneous.
• Larger cache sizes help with multitasking as well, since
background tasks will be ready for when you switch focus to
another window.
• On currently available desktop processors, i5 CPUs have 3MB
to 8MB of L3 cache, while i7 processors have 8MB to 15MB.

29. Turbo Boost feature
• Turbo Boost refers to Intel's "overclocking" feature
built into its processors.
• It allows the processor to run faster than its base clock
speed when only one or two processor cores are needed
(like when you're running a single-threaded task that you
want done now).
• This provides users with the opportunity to turn off a core if
it’s not being utilized.
• Both Core i5 and Core i7 processors use Turbo Boost

30. Hyper-Threading
• Intel Hyper-Threading uses multi-threading technology to
make a processor appear to have more cores than it
physically has to the operating system and applications.
• Hyper-Threading technology is used to increase
performance at multi-threaded tasks.
• The simplest multi-threaded situation is a multi-tasking user
running several programs simultaneously, but there are
other tasks that take advantage of Hyper-Threading
• For instance multimedia operations (like transcoding,
rendering, etc.) and Web surfing (loading different elements
like Flash content and images simultaneously).

31. Hyper-Threading Cont…
• All Core i7 CPUs use Hyper-Threading,
• A six-core CPU can handle 12 streams
• Four core handles eight streams, and a dual-core handles
four streams.
• Core i5 uses Hyper-Threading to make a dual-core CPU act
like a four-core one, but if you have a Core i5 processor with
four true cores, it won't have Hyper-Threading.
• For the time being, Core i5 tops out at handling 4 streams,
using four real cores or two cores with Hyper-Threading.

32. Hyper-Threading …

33. Integrated Graphics
• Integrated graphics built into the processor core itself.
• Previous Intel integrated graphics were built onto the
motherboard chipsets, rather than on the processor.
• Intel HD Graphics 2000/3000 in currently shipping Sandy
Bridge processors.
• Integrated graphics saves power, since there won't be an
extra graphics chip on your laptop or desktop's motherboard
using power.

34. Conclusion
• Multi-core chips an important new trend in computer
architecture
• Several new multi-core chips in design phases
• Parallel programming techniques likely to gain importance
• Turbo boost feature is implemented after Core i5 design. So
it is main feature of corei5.
• Core i5 has Dual and Quad Core Both.
• Core i5 is made for mainstream users who care about
performance and core i7 is made for enthusiasts and high-end
users.