btec level 3 unit 2 1 -...
TRANSCRIPT
Stores:
The Operating System
Application files
User data
3.5 inch units in servers and desktops
2.5 inch units in notebooks and external drives
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A typical hard disk today, would provide 250 GBs with an access time of 8.5 milliseconds, compared to 10 MBs and access times of 87 milliseconds in the 1980’s.
Hard Disk Video
Platter – “Is the actual disk”, made from aluminium or glass and are therefore hard/solid as apposed to floppy disks, the actual platter is not magnetic.
Coating – The Platter is typically coated in a magnetised (Iron-Oxide) material (Cobalt oxide in new disks), to allow it to store a magnetic pattern that will represent the computers data.
The future looks to be Solid State hard drives.
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Platter/s 2 writeable sides, magnetic coating
Tracks Concentric circles
Sectors Typically 512 bytes
(smallest storage unit of the hard disk)
Cylinders?
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Cylinders – when hard disks have more than one platter, the read/write heads are mechanically linked and are therefore placed over a set of tracks at any one time !
This collection of tracks is known as a cylinder.
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Question – How many tracks are being read on the above image at any time?
A more recent permanent storage technology
Faster read and write access
Typically a 2.5 inch drive
Less power, heat and
No moving parts.
Can withstand more vibration.
More expensive than traditional drives.
4TB soon to be 8TB (SanDisk)
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Three main standards:
PATA Parallel Advanced Technology Attachment
SATA Serial Advanced Technology Attachment
SCSI Small Computer System Interface
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Principal interface for many years
Two drive controllers
IDE 1 or PRI IDE
IDE 2 or SEC IDE
Motherboards with SATA typically have one PATA for compatibility
One IDE (Integrated Drive Electronics) channel
supports 2 devices – a master and a slave
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40 pin connector
80 wire shielded cable required for UDMA4 or better
Colour coded “cable select” cables avoid “master/slave”
How to cable?
Motherboard connector – blue
Master connector – black
Slave connector – grey
Pin 1 has a red stripe
Connectors are keyed
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Record the manufacturer name, size (3.5/2.5) and capacity of the hard disks within the PC.
Is the drive IDE or SATA?
Is the drive connected to the Primary/secondary controller?
Is the drive configured as a master or slave?
Is the cable the correctly orientated?
we will later confirm this within the BIOS.
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Hot Swappable
No Master and Slave configuration
Original standard support for 150 MBps and now 300,MBps, 6 gbps
Universal connector for 2.5/ 3.5 drives and servers
eSATA allows for external connection with 2M cable
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•Parallel
•Serial
•Input/Output
•Male/Female
Cabling
•Twisted pair
•Coaxial
•Optical
RAM – Random Access Memory
ROM – Read Only Memory
Cache – Fast memory that does not need to be refreshed. L1Cache
L2 Cache
L3 Cache
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L1-cache
The fastest cache and it usually comes within the processor chip itself.
L1 cache typically ranges in size from 8KB to 64KB and uses the high-speed SRAM (static RAM) instead of the slower and cheaper DRAM (dynamic RAM) used for main memory.
The Intel Celeron processor uses two separate 16KB L1 caches, one for the instructions and one for the data.
L2-cache
Lives between L1 and RAM (processor-L1-L2-RAM) and is bigger than the primary cache (typically 64KB to 4MB).
L3-cache
Not found nowadays as its function is replaced by L2 cache. L3 caches are found on the motherboard rather than the processor. It is kept between RAM and L2 cache.
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SDRAM – Random Access Memory
This is where software and programs once loaded are stored (re-open application).
When the CPU runs a program it fetches data from the RAM.
RAM is volatile – which means it can be, changed destroyed ,deleted and replaced when needed.
Currently a DIMM format
Sizes of DDR2 2GB (8GB) to DDR4 64 GB (128GB).
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Identify the location of the RAM inside the given PC
Remove the RAM, identify the RAM size if possible by reading the label.
Check for notches , align RAM, reinstall the RAM.
Using CPUz identify the amount of RAM within the college computers in T104.
How many RAM slots are there on the motherboard?
What is the current size of RAM memory inside the PC? (the motherboard manual will typically confirm the maximum size).
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Basic Input Output System
Firmware located on the Motherboard that is loaded when the computer is first switched on.
Identifies and checks the system hardware
Carries out POST (Power On Self Test)
Prepares a system to boot an Operating System.
Many types exist, Phoenix, Award, Ami , etc.
An example of a ROM (EEPROM)
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A replacement for the BIOS system, yet supports BIOS services.
UEFI is a specification detailing an interface that helps to hand off control of the system for the pre-boot environment (i.e.: after the system is powered on, but before the operating system starts).
Benefits include:
Support for new standard such as iPV6 (iPV6 network boot - iSCSI, PXE)
Improve boot graphics (Safe Mode Video)
New authenticated boot scenarios
32-bit protected mode as being a native mode of operation– Support for > 2TB hard diskComputer Components 20
Specialised cards (generally PCI or PCI-e bus)
Networking
Sound
Additional ports
Considerations
Bus type
Free Space
Device Driver (correct software)
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How to remove and install an expansion card?
Blanking plates
Screw or retain the card
Ensure the card is found by the Operating System.
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which processor cache is quickest to fetch/store data L1 or L2?
How much cache can be found on a typical AMD Quad core processor?
Which other PC component also includes a cache?
What memory type is the fastest -SRAM or SDRAM?
Modern RAM is found in which format DIMM or SIMM or Rambus?
Explain the term “firmware”.
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