Hardware and SoftwareIn order to run, an information system will require:HardwareSoftware

Hardware and SoftwareThe hardware requirements will include:Input devicesOutput devicesComputer with suitable processor and memoryBacking storage

Hardware and SoftwareIn addition, consideration will need to be given to the device type

All computers also require an Operating System to be installed

Input DevicesAs well as common input devices such as keyboard and mouse, we also need to consider:TouchpadScannerBarcode readerDigital cameraDV cameraWebcamGraphics tabletTouch screenJoystickMicrophone

Output DevicesOutput devices include:Monitor (CRT replaced by LCD and TFT displays)Laser printerInk jet printerFlatbed plotter3D printerSpeakers / headphonesProjector

ProcessorFactors to consider when choosing a processor:Type / manufacturerClock speedNumber of cores

ProcessorThe two main processor manufacturers are:IntelAMD

Each manufacturer offers a wide range of different processors.

Which one is best? It depends on what the processor has to do.AMD tends to be slightly cheaper, good for budget gamingIntel tends to be more powerful for high end tasksFairly irrelevant if all that’s required is basic word processing / web browsing

ProcessorClock speed

Every computer contains an internal clock that regulates the rate at which instructions are executed and synchronizes all the various computer components.

The CPU requires a fixed number of clock ticks (or clock cycles) to execute each instruction. The faster the clock, the more instructions the CPU can execute per second.

Clock speeds are expressed in gigahertz (GHz).

One gigahertz = 1 billion clock cycles per second.

ProcessorNumber of Cores

A multi core processor is a single component with two or more processing units (cores)

Until 2005 all CPUs were single core. Today multi core processors are commonly dual or quad core, but 8 core and 16 core are also available.

ProcessorNumber of Cores

Is a dual core processor twice as fast as a single core processor (assuming all other characteristics are identical)?Not necessarily. It depends on what the processor is actually doing.The greatest improvement will be when multitasking 2 different tasks at the same time rather than trying to do the same task twice as fast.

MemoryRAM

More RAM means that more programs and their associated data can be stored in memory at any time.

RAM is solid state – no moving parts which makes data transfer fasterRAM is volatile – contents are lost when not poweredRAM is measured in gigabytes (GB)

MemoryRAM

More RAM means that more programs and their associated data can be stored in memory at any time.

In 2016 a typical desktop computer will come with between 2GB and 16GB RAMIf there is insufficient RAM to hold the OS, open programs and data, the computer will use “virtual memory” on the hard drive instead. This is much slower.Uses Dynamic Random Access Memory (DRAM) which is slow because the electric charge needs to be constantly refreshed and CPU cannot access RAM during the refresh

MemoryCache Memory

Cache memory is a small amount of fast access memory

Cache is faster than main memory because:Built into the processor, or located next to it on a separate chipUses Static Random Access Memory (SRAM) rather than DRAM used by main memory. SRAM does not need to be refreshed.Data transfer is faster than transfer using the data bus

MemoryCache Memory

MemoryCache Memory

L1 vs L2 Vs L3 cache

L1 cache is closest to the core (each core has its own cache) and typically there are one for data and one for instructions, sizes are 8-64KB

L2 can be shared with multiple cores and is in the 2-4MB range

L3 is on the die as well in some systems and can be 8-16MB, although some processors have replaced it with L2 cache

BenchmarksGiven the wide range of processors available, and other aspects of the hardware configuration which can impact on performance, it is difficult to compare different computer systems.

When comparing different processors, a range of standard benchmark tests are carried out and a score awarded.

Benchmarks

BenchmarksBenchmark tests can be run on computer systems, evaluating how well they will cope with real world tasks (gaming, video editing etc.)

Device Types Desktop computer – larger in size, easier to customise

components, requires connection to input/output devices. Laptop computer – mobile, more expensive than desktop due to

need to fit components into smaller space Tablet – touch screen, no moving parts Mobile phone – typically smaller than tablet, has ability to make

phone calls via SIM card

Device Types Supercomputer – large, very fast, very expensive, used in fields

like weather forecasting and areas where many fast calculations are required

Mainframe – similar to supercomputer but where a supercomputer will be focused on completing one task very quickly, mainframe tends to process many programs at the same time