Hard Disk Drive upgrades from MK-x Computing    

MK-x Computing

MK-x Computing

Please Note;   MK-x Computing is now part of the A&A Computers - Genner Communications Group.

HDD (Hard Disk Drives); A Short Overview

Note; A Hard Disk Drive can also be referred to as a HDD, a Hard Disk or a Hard Drive

    There are many different types of hdd (hard disk drive). Desktop & tower PC`s tend to use 3.5" IDE hard drives (although some used 5.25"), whilst laptops tend to use 2.5" hard drives.

    Although both IDE, the connections on 3.5" & 2.5" drives are totally different MK-x can supply an adapter so that data can be transferred from a 2.5" to 3.5" or visa versa.

   

    2.5" & 3.5" IDE hard drives are not alike.

    25" IDE hard drives connect to the PC via 44 pins

    3.5" IDE hard drives connect to the PC via 40 pins

    MK-x can advise exactly which drive you need.

For a PC to be able to communicate with & transfer data to & from an IDE Hard Disk, it needs to understand certain details about the drive. This information is stored in the computers BIOS (Basic Input Output System) & most modern PC`s automatically scan for IDE hard drive information upon start-up, retain the information & expect the drives to be constantly present. For this reason, MK-x can supply removable hard drives, but do not supply hot pluggable IDE drives (drives which can be removed without switching the PC off).

3.5" IDE Hard Disk Drives

 

    The diagram above shows a 3.5" IDE connection.

    The photo on the left shows the same connection.

   

The IDE cable connects to the red pins.

The yellow pins are "jumper connections".

    Please note that jumper configuration varies between types & models of hard drive, However, there are 3 basic types of configuration & all of them are selected by either fitting jumpers (small plastic blocks with metal inserts) to the jumper connections, or removing them (white jumpers have been fitted to the drive in the above photo).

    2 IDE hard drives can be connected to an IDE cable. One hard disk will be referred to the Master, the second as the Slave.

    The PC needs to be told which hard disk is which & this is the primary function of the jumper pins. In the diagrams below, jumper setting are shown by yellow lines.

This would usually set the hdd to Master (M)

This would usually set the hdd to Slave (SL)

This would usually set the hdd to Cable Select (CS)

    Cable select is where the PC effectively decides which hard disk should be the Master & which hard disk should be the Slave. Although many major manufacturers eg; Compaq & HP usually set their drives to cable select, I personally prefer not to use this feature (I would rather keep control of configuration settings & manually set a drive to either Master or Slave). However; some systems "insist" on using CS.

Note; If using a third party hard drive controller (a hard disk controller which fits into a PCI slot & either supplements or replaces the original controller, the hard disk will usually not be seen unless it is configured as either master or slave. 

This would usually be capacity limit. This feature is not available on all hard disks drives and should not be needed on the latest specification PC`s. This feature is designed to "get around" issues where the PC cannot use drives above a certain capacity. eg; If a PC cannot see or use a drive larger than 32gb & you have an 80gb unit, using this feature limit the drive capacity so that it may be seen by the PC.

    Note; The capacity available varies between drives. eg; some hard disk drives have a capacity limit of 8gb, some are 16gb, some are 20gb, some are 32gb etc.

This would usually set the drive to Master, with the drive capacity limited.

    Note; always read the Hard Drive fitting instructions & configure the drive accordingly.

Drive Performance

    There is much confusion about drive speeds etc & the ability of some systems to use high performance IDE drives. The performance of new drives is determined by a number of factors such as the RPM & ATA rating.

RPM;    Rotations Per minute. If a hard disk drive is a box of disks, the RPM is the speed at which they spin. The faster they spin, they faster data can be accessed. For this reason IDE hard disk drives have been available as 4200rpm, 5400rpm & 7200rpm units.

ATA;    The IDE hard disk drive connects to the PC via an IDE cable, & the hard disk drive will be able to transfer data at a given maximum speed. This speed is referred to as ATA33, ATA66, ATA100, ATA133 & ATA166. However if the PC cannot match the drives transfer speed, or the drive cannot match the PC`s transfer speed, then the data will travel at the speed of the slowest component (the drive or the board). Similarly; speeds above ATA33 require the use of a special high density cable (supplied with MK-x Drives). If this cable is not used, then even the fastest drive can only transfer data at ATA33.

Configuring drives for different operating systems

    Mk-x regularly upgrade systems systems running Windows 95, Windows NT4, Windows 98, Windows ME, Windows 2000 & Windows XP & I will deal with each of these in order. But first; I need to provide a basic explanation of the different file systems (the way in which data is stored, arranged & accessed on a hard drive).

Types of Partition

Types of Windows Operating Systems

Configuring a hard drive to work with Windows systems

MK-x Computing provide a free telephone/email help/advisory service for MK-x customers who are installing an MK-x Drive.

2.5" (Laptop) Hard Disk Drives

2.5" hard disk drives tend to be used in laptops & rather than having 40 pins & a separate power connection (like 3.5" IDE drives), they have 44 pins with the extra pins being used for power. Additionally; rather than having 3 or 4 rows of jumper pins, a 2.5" drive will usually have 2 rows. The default setting will typically be; no pins connected.

Note;    Many 2.5" hard disk drives rattle when moved. This is normal for most hard drives & is simply part of the hard disks shock absorbing technology (these drives are designed to be transportable).

This diagram shows the IDE interface in red & the jumper connections in yellow. Jumpers for 2.5" drives are much smaller than those used on 3.5" units.

    Laptop hard disk drives are often supplied in special removable caddies which are unique to a particular model or manufacturer. MK-x engineers can fit a new drive into your existing caddy &/or transfer the contents of the old drive to the new unit.

Note;    Laptop hard disks should never be fitted or removed whilst the PC is switched on.

SCSI Hard Disk Drives

    SCSI (pronounced "skuzzy") hard drives tend to be used in servers because server data is usually critical. SCSI hard disks tend to be faster & more reliable than IDE, & whilst each IDE connection can have 2 devices or drives attached, each SCSI connection can have up to 15 devices or drives. However, SCSI devices require a special controller & connections (usually a separate SCSI controller card which plugs into a PCI slot), they are also more expensive & the SCSI hard disk drive connections vary. The most common tend to be 50 pin (also known as narrow or fast SCSI), 68 pin (also known as wide or fast wide SCSI) & 80 pin (also known as ultra wide or SCA SCSI). Note; the type of connection is all important when selecting a hard disk drive, because some manufacturers have been known to use conflicting terms (what one manufacturer or dealer calls Fast SCSI, another may call Wide SCSI).

    SCSI hard disk drives may also need to be configured to work with a particular system. The SCSI controller will scan for new hard drives & devices upon start up, but will need to differentiate between individual hard disk drives & devices. For this reason each device is given a SCSI ID number. Although wide SCSI can control 16 devices, one of these will be the controller itself. The controller is usually configured as SCSI ID 0. The SCSI ID for every other device will either be allocated by the SCSI controller, or defined by setting jumpers on drives switches on devices such as scanners etc, & through software on intelligent SCSI units such as MK-x RAID boxes.

   "Here Be Wisdom"; a SCSI device can be a "box" of drives. This "box" can contain a special SCSI controller which is connected to a maximum of 15 drives probably configured as a RAID set (see below). Because the "box", controller & drives is effectively a separate device, this will only use 1 SCSI ID, which means that up to 15 "boxes" can be attached, each of which can contain up to 15 drives.

Hot Pluggable SCSI Hard Disk Drives

    Hot pluggable hard disk drives are so called because they can be fitted or removed from a system whilst the machine is active (this practice is not recommended by MK-x). Hot Plug hard disks are typically supplied in a special manufacturers caddy & require a suitable SCSI controller. Because of this, the hard disk drive industry developed SCA drives. These are SCSI units which are specifically designed to be hot pluggable & use an 80pin ("D" type connection in the centre rear of the drive & do not have a power connector). These can be easily fitted to many manufacturers Hot Plug caddies.

RAID 0, RAID 1, RAID 3, & RAID 5

    A RAID set is simply a group of hard disk drives which is seen as a single drive (thus increasing performance). Most Servers tend to use SCSI hard disks which may or may not be configured as RAID sets. & the most popular RAID systems tend to be RAID 5 & RAID 0.

Note;    Hard Disk Drives used in RAID sets should be identical units.

    RAID 0    RAID 0 provides no redundancy (if a hard disk drive fails, the data is lost). Data is simply spread over 2 or more drives which are then treated as a single unit, thus providing improved performance.

    RAID 0    RAID 1 is where data is mirrored (copied) to additional hard disk drives in order to provide redundancy (if a hard disk drive fails, the data is still available on another drive). Hard Disk Drives configured as raid 1 should always be fitted in pairs

    RAID 0    RAID 3 is a system which allows data to be transferred & stored at the the highest possible rate. In Raid 3, data is spread over a number of hard disk drives & one hard drive is dedicated to providing parity (a single hard drive is dedicated to storing information on about the data on the other hard disks).

    RAID 0    RAID 5 requires a minimum of 3x hard disk drives to be attached. All data is spread over & duplicated on the hard drives. This means that the capacity of one drive is effectively lost, but if any hard disk fails, no data will be lost (this is referred to as redundancy). When the faulty hard disk drive is replaced, the RAID set will normally be rebuilt, thus providing redundancy again.

    Due to the improved speed & reliability of modern IDE hard disk drives, these can now be used as part of a RAID set & can even be supplied pre configured in an external "box". Although not as reliable or quick as true SCSI units, they are considerably cheaper.

    All hard disk drives used in RAID sets should be identical units (identical model, capacity & firmware version). Since RAID is a "High End" storage system, it is highly recommended that a "High End" operating system is used with RAID units. We would therefore suggest that only Windows NT4 (SP 5 or above), Windows 2000 Professional, Windows 2000 Server, Windows 2003 Server or Windows XP Professional be used on the host machine & that NTFS be used to format the RAID units. Client machines (PC`s which access data on the RAID units) should be running Windows 98 SE or above.

Overview by Kevin Genner

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Please note;    MK-x does not necessarily agree with comments made or advice given by Kevin Genner or other contributors.

Postal Address;    MK-x Computing (Genner Communications), PO Box 653, Telford. TF3 1ZN.

Simply click on your Brand of PC

Clone pc`s        Please click here for general information on Clone computer upgrades

This section deals with details of general hard drives, sound cards, graphics cards etc available for general (clone) PC systems.

Compaq        Please click here for details of our Compaq upgrades (Compaq compatible computer upgrades)

This section contains details of Compaq Hard Disk Drive upgrades (Compaq HDD upgrades), Compaq graphics card upgrades (Compaq video card upgrades), Compaq sound card upgrades, Compaq DVD ROM upgrades & Compaq CD writer upgrades / Compaq DVD writer upgrades.

Dell        Please click here for details of our Dell upgrades (Dell compatible computer upgrades)

This section contains details of Dell Hard Disk Drive upgrades (Dell HDD upgrades), Dell graphics card upgrades (Dell video card upgrades), Dell sound card upgrades, Dell DVD ROM upgrades & Dell CD writer upgrades / Dell DVD writer upgrades

Compaq        Please click here for details of our emachines upgrades (emachines compatible computer upgrades)

This section contains details of eMachines Hard Disk Drive upgrades (eMachines HDD upgrades), eMachines graphics card upgrades (eMachines video card upgrades), eMachines sound card upgrades, eMachines DVD ROM upgrades & eMachines CD writer upgrades / eMachines DVD writer upgrades

Fujitsu Siemens    Please click here for details of our Fujitsu upgrades (Fujitsu compatible computer upgrades)

This section contains details of Fujitsu Hard Disk Drive upgrades (Fujitsu HDD upgrades), Fujitsu graphics card upgrades (Fujitsu video card upgrades), Fujitsu sound card upgrades, Fujitsu DVD ROM upgrades & Fujitsu CD writer upgrades / Fujitsu DVD writer upgrades

HP (Hewlett Packard)    Please click here for details of our HP upgrades (HP compatible computer upgrades)

This section contains details of HP Hard Disk Drive upgrades (HP HDD upgrades), HP graphics card upgrades (HP video card upgrades), HP sound card upgrades, HP DVD ROM upgrades & HP CD writer upgrades / HP DVD writer upgrades

IBM    Please click here for details of our IBM upgrades (IBM compatible computer upgrades)

This section contains details of IBM Hard Disk Drive upgrades (IBM HDD upgrades), IBM graphics card upgrades (IBM video card upgrades), IBM sound card upgrades, IBM DVD ROM upgrades & IBM CD writer upgrades / IBM DVD writer upgrades

Networking    Computer Networking

Utility CD`s

 Please Note;

If you cannot find the correct Hard Disk Drive for your system, please call A&A Computers - Genner Communications.

Desktop PC HDDs Tower PC HDDs Laptop HDDs

Recovery CD`s

Most Computers were originally supplied with one or more Windows Recovery CDs or DVDs (also known as hard drive Restore CDs or DVDs). These disks usually contain an image of what was on the computers hard drive when it was first bought, & they allow you to return the machine to its original state. This is particularly useful if the machine has been attacked by a virus, if the original hard drive has developed a fault, or if you simply wish to replace or upgrade the hard drive, & need to re-install your software.

Genner Sales can supply the following Windows Repair CDs, Windows Recovery CDs & Windows Restore CDs.

   Windows Repair CDs & Windows Recovery CDs     Genner Sales Hard Drive Recovery CDs Home Page.

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