Chapter 9 Hard Drive Technologies (220-901)

Native Command Queuing (NCQ)

A disk optimization feature for SATA drives. It enables faster read and write speeds.

AHCI (Advanced Host Controller Interface)

AHCI unlocks some of the advanced features of SATA, such as hot-swapping and native command queuing. When you plug in a SATA drive to a running Windows computer that does not have AHCI enabled, the drive doesn't appear automatically. In Windows Vista, you need to go to the Control Panel and run the Add New Hardware to make the drive appear, and in Windows 7 and later, you need to run "hdwwiz.exe" from the Start menu Search bar. With AHCI mode enabled, the drive should appear in Computer immediately. You can enable AHCI in the CMOS if you want it enabled because if you enable it after you install the OS you will get a BSoD There is a way to do it if you have the OS downloaded. Go to Microsoft's website to check it out.

S.M.A.R.T. (Self Monitoring And Reporting Technology)

An internal drive program that tracks errors and error conditions within the drive. This info is stored in nonvolatile memory on the drive and must be examined externally with S.M.A.R.T. reader software. Regular usage of S.M.A.R.T. software will help you create a baseline of hard drive functionality to predict potential drive failures.

Parallel ATA (Parallel Advanced Technology Attachment)

Around the 1990s an interface called PATA came around (PATA is also called IDE). PATA drives can support 2 drives on one channel, but when you install them make sure you set the fastest drive to master and the slowest to slave (If you only have one drive set it to single or master). All PATA drives use a standard Molex power connector.

Hot-swapping

Being able to plug a device into the computer without harming wither. Once the device is safely attached, it will be automatically recognized and become a fully functional component of the system. SATA handles hot swapping just fine.

Hard Disk Drive (HDD)

Composed of individual disks, or platters, with read/write heads on actuator arms controlled by a servo moto all contained in a steel case. HDDs are magentic and have movinf parts so be sure to keep them away from magnets or it will wipe the drive.

Spindle (or Rotational) Speed

Hard drives run at a set spindle speed, with spinning platters measured in revolutions per minute (RPM). Older drives ran at a speed of 3600 RPM , but newer devices are hitting 15,000 RPM. The faster the RPM, the faster the controller can store and retrieve data. Common speeds are: 5400, 7200, 10,000, and 15,000 RPM. Watch for heat cause heat can dramatically reduce the life of your hard drive.

Autodetection

If the controllers are enabled and the drive is properly connected, the drive should appear in this process. This feature takes all of the work out of configuring hard drives.

RAID 0+1 (Redundant Array of Independent Disks)

Like RAID 10, RAID 0+1 is known as Nested, Striped Mirrors. It takes four drives to implement RAID 0+1. Start with two RAID 0 striped arrays, then mirror the two arrays to each other.

Connecting SSDs

M.2 and mSATA drives slip into their slot on the motherboard or add-on card, then either clip in place or secure with a tiny screw. Both standards are keyed, so you can't install them incorrectly.

pin 1

On PATA and Mini Floppies have a color stripe that corresponds to the number-one pin. You need to make certain that pin 1 on the controller is on the same wire as pin 1 on the hard drive. Failing to plug in the drive properly will also precent the PC from recognizing the drive.

RAID 0 (Redundant Array of Independent Disks)

RAID 0 is known as disk striping and it requires at least 2 hard drives to work. This does not provide redundancy to data. If any one drive fails all data is lost. (Basically here's how it works. If you have the word "gang" it will get split up. "g" will go to hard drive 1, "a" will go to hard drive 2, "n" will go to hard drive 1, and "g" will go to hard drive 2.)

RAID 1 (Redundant Array of Independent Disks)

RAID 1 is known as mirroring and it requires at least 2 drives. RAID 1 is ultimate in safety, but you lose storage space because the data is duplicated. You need two 2-TB drives to store 2 TB of data. (For example, if you have the word "read", the word will go to both hard drives.)

RAID 10 (Redundant Array of Independent Disks)

RAID 10 is known as Nested, Striped Mirrors. You need a minimum of four drives. Basically, a pair of drives is configured as a mirror, and then the same is done to another pair to achieve a pair of RAID 1 arrays. The arrays look like single drives to the OS or RAID controller. So now with two drives we can block stripe across the two mirrored pairs (RAID 0).

RAID 5 (Redundant Array of Independent Disks)

RAID 5 is known as Disk Striping with Distributed Parity and it requires at least 3 drives. This RAID combines RAID 1 and RAID 0. That means this set up can have redundancy and increases your performance. So your drive can mirror your data and have better performance. Also, if you have three 3-TB drives your total storage capacity is 4 TB.

RAID 6 (Redundant Array of Independent Disks)

RAID 6 is known as Disk Striping with Extra Parity. This is like RAID 5 but with extra parity information. RAID 6 needs at least 5 drives, but in exchange you can lose up to two drives at the same time.

Serial ATA (Serial Advanced Technology Attachment)

SATA makes a point-to-point connection. This means it does not share the channel with any device. SATA did away with the Master/Slave concept. Data transfers: SATA 1.0: 150MBps (1.5Gbps) SATA 2.0: 300MBps (3 Gbps) SATA 3.0: 600MBps (6 Gbps) SATA 3.2: (16Gbps) Way faster than IDE/PATA drives

Cable lengths

SATA: 1 meter PATA: 18 inches eSATA: 2 meter

SATAe

SATAe (SATA 3.2), ties capable drives directly into the PCIe bus on the motherboards. SATAe plugs directly into the PCIe slot. SATAe is extremely fast and it has speeds up to 8Gbps and a drive with two lanes would be 16Gbps.

eSATA (External SATA)

Sends the SATA bus to external devices. eSATA connectors are similar to SATA connectors but they are keyed differently so you don't get them confused.

NVMe (Non Volatile Memory Express)

Supports a communication between the OS and the SSD directly through a PCIe bus lane, reducing latency and taking full advantage of the wicked-fast speeds of high-end SSDs. NVMe SSDs come in a couple of formats, such as an add-on expansion card and a 2.5 inch drive. NVMe drives are a lot more expensive currently than other SSDs, but offer higher speeds.

boot order

The boot order determines which drive will boot first. You might want to set up a boot order that goes optical drive, hard drive, and then USB thumb drive.

Hybrid Hard Drives (HHDs)

These drives combine flash memory and spinning platters to provide fast and reliable storage.

Solid State Drive (SSD)

They are way faster than hard drives because of they have no moving parts. SSD is all flash based memory, which is why it's faster. They use memory chips to store data instead of spinning metal parts used in platter-based hard drives. SSD form factor are usually 1.8 inch, 2.5 inch, or (rarely) 3.5 inch. SSDs also come in mSATA (used in portable devices) and M.2 (connect directly to special slots on the motherboard.) and SSDs can come on an expansion slot. SSDs are really expensive compared to the HDDs.