Difference Between i3 and i5

Core i3 and Core i5 are processors that belong to the family of Intel Core processors. There are three generations of Intel Core processors and hence three generations of Core i3 and Core i5 processors. In each generation, there is a series of Core processors for desktop computers and a series of processors for mobile computers. Before we look into the features of these processors and where they are used, let us first understand how the processors are named.

Before going into key technical differences between i3 and i5, lets try to understand about intel processors, their naming and other important aspects.

Intel Core Processors Nomenclature

The third and second generations of Intel Core processors have similar rules for processor numbers. The name of the processor always starts with the brand name which in this case is 'Intel Core'. This is followed by an alpha/numeric modifier (e.g. i3, i5) which is also called the brand modifier. Next comes a 4-digit numerical sequence which uniquely identifies the processor. The leftmost digit of the numerical sequence indicates the generation (2 for second generation and 3 for third generation). The processor number may have alpha suffixes depending on the processor.

The first generation of Intel Core (more commonly referred to as Previous Generation Intel Core processors) processors have only a 3-digit numerical sequence following the brand modifier. A higher processor number within a family generally indicates more features. The table below summarizes the relation between processor numbers and their type.

Before moving on to the features, let us see definitions of certain technical terms which are used in the specifications of these processors.

Technical Terms

Cores: It is a hardware term that describes the number of independent central processing units in a single computing component or a processor. A multi core processor gives enhanced and more efficient performance since there are two or more CPUs working simultaneously. All Core i3 processors have 2 cores. Core i5 processors may have 2 or 4 cores. Quad core CPUs perform better than dual core CPUs on multimedia tasks like video and photo editing.

Threads: A Thread is a software term for a sequence of instructions that can be processed by a single CPU core independent of the other CPU cores in the processor. In a multi-thread environment, each of the threads can be executing concurrently. Generally, one CPU core can run only one thread. But Intel has come up with a feature called hyper-threading which allows two threads to be run by a single CPU core. Core i3 processors support hyper-threading due to which in spite of having only 2 cores they can run 4 threads at a time. Core i5 processors do not support hyper-threading, so even if they have 4 cores they can run only 4 threads.

Lithography: Lithography refers to the semiconductor manufacturing technology used to manufacture the processor. It is the process of transfer of pattern to a photosensitive material by selective exposure to radiation. Selective exposure is achieved by using masks and photo resist materials. The measurements for size of mask and areas that are exposed or not exposed to radiation are made in multiples of a standard value which is measured in nanometers. For example, if a processor is manufactured by using measurements in multiples of 22nm, then it is said to have been manufactured using 22nm technology.

Code Name: Intel uses internal code names to identify products that are in development and not yet released commercially. Ideally, the code name must cease to exist after the release of a product with its commercial name. However, most times these code names continue to be used to identify the type of micro architecture used in that product. Intel generally uses names of geographical places which cannot be trademarked as code names to avoid any risk of legal problems. Some of these code names which are used for Core i3 and Core i5 processors are as given below:

• Arrandale– Arrandale is the codename for a two core mobile processor. Arrandale is comprised of a 32nm processor core and 45nm graphics and memory controller integrated in a multi-chip package. Previous generation Core i3 and i5 mobile processors use Arrandale micro architecture.
• Clarkdale– Clarkdale is the codename for a two core desktop processor. Clarkdale is also comprised of a 32nm processor core and 45nm graphics and memory controller integrated in a multi-chip package. Previous Generation Core i3 and i5 desktop processors use Clarkdale micro architecture.
• Sandy Bridge– It is the evolution of the Nehalem micro architecture and is generally used to refer to the associated family of 32nm processors based upon that micro architecture. Second generation Core i3 and i5 processors use this micro architecture.
• Ivy Bridge– It is the 22nm version of the Sandy Bridge micro architecture. This architecture is used by third generation i3 and i5 processors.

Cache: It is a high-speed memory storage area close to the CPU that has a lesser access time than the main memory. Cache memory is expensive and hence limited in capacity. Core i5 processors generally have larger cache size than i3 processors.

Bus Type: A bus is a subsystem that transfers data between computer components or between computers and can be of different types. Direct media interface (DMI), which is a point-to-point interconnection between an Intel integrated memory controller and an Intel I/O controller hub on the computer's motherboard, is the bus type that has been used in all i3 and i5 processors.

System Bus: It refers to the bus speed and is measured in gigatransfers per second or GT/s.

Instruction Set: An instruction set refers to the set of all commands and instructions that a microprocessor understands and can execute. These are the set of instructions that are used to program the processor. All i3 and i5 processors use a 64-bit instruction set, i.e. every instruction is 64-bits wide in binary.

Instruction Set Extensions: Instruction Set Extensions are additional instructions which increase performance when the same operations are to be performed on multiple data objects. These can be SSE (Streaming SIMD Extensions) or AVX (Advanced Vector Extensions). SSE introduces a new set of Single instruction multiple data (SIMD) instructions which greatly improve the performance of applications such as video encoders, image processing, 3D games and string/text processing. AVX is 256-bit instruction set extension to SSE and is used for applications that are floating point intensive. It was released in early 2011 as part of Sandy Bridge micro architecture.

Memory Specifications:

1. Maximum Memory Size: It refers to the maximum memory capacity (in GB) supported by the processor.
2. Number of Memory Channels: All Core i3 and i5 processors have 2 memory channels which handle memory processing more efficiently in real world applications by utilizing the theoretical bandwidth of the two memory modules. This reduces system latencies and improves timing performance.
3. Maximum Memory Bandwidth: It is the maximum rate at which data can be read from or written to memory by the processor (in GB/s).
4. Physical Address Extensions (PAE): It is a feature that allows 32-bit processors to access a physical address space larger than 4 gigabytes (2^32=4GB).
5. Error-correcting Code (ECC) Memory: It is a type of system memory that can detect and correct internal data corruption. Some processors support this feature, while some do not.

General Features of Core i3 and Core i5

Core i3 and i5 have many differences between them, but they also have the following features in common:

• • Number of Threads: 4
  • Bus Type: DMI
  • 64-bit Instruction Set
  • 2 Memory Channels

Core i3

Core i3 processors give good performance for common tasks like listening to music, checking emails and banking. All Core i3 processors are dual core processors.

Previous Generation Core i3 processors have the following specifications:

• • System Bus: 2.5GT/s
  • Lithography: 32 nm
  • 36-bit Physical address extensions

Second Generation Core i3 processors have the following specifications:

• • Code name: Sandy Bridge
  • 3 MB Cache
  • System Bus: 5GT/s
  • Lithography: 32nm

Core i5

These processors are better for media creation, multitasking and faster speed. Core i5 processors have a technology called Turbo Boost which lets them to dynamically increase the clock speed when the need arises.

Previous Generation Core i5 processors have the following specifications:

• • System Bus: 2.5 GT/s
  • 36-bit Physical Address extensions

Second generation Core i5 processors have the following specifications:

• • Processor Number: 2xxx
  • Code name: Sandy Bridge
  • System Bus: 5GT/s
  • Lithography: 32nm

Third Generation Core i5 processors have the following specifications:

• • Code name: Ivy Bridge
  • System Bus: 5GT/s
  • Lithography: 22nm
  • Maximum Memory size: 32 GB
  • Maximum memory bandwidth: 25.6GB/s
  • ECC memory is not supported

Third Generation Core i5 processors for desktop computers use Instruction Set Extensions SSE4.1/4.2 and AVX.

Third Generation Core i5 processors for laptops or mobile computers are dual core, have a cache size of 3MB and use AVX Instruction Set Extensions.

Key Technical difference between Core i3 and Core i5

These are key tech differences between i3 and i5. For a user point of view, if you are looking a processor for normal daily work i3 will work very fine. But in case you need to do some heavy duty work, bit of gaming, running processor intensive s/w i5 is recommended.