Home / PC Guides and Tutorials / The PC Storage Guide for the Masses
storage guide

The PC Storage Guide for the Masses

  1. Introduction
  2. Internal Drives Connectivity Options
  3. External Drives Connectivity Options
  4. Storage Method: Mechanical Drives
  5. Storage Method: Solid-State Drives
  6. Stuff to check before purchasing storage
  7. View All

  • SATA

Serial-ATA (short for SATA) the most common interface for internal storage drives- both for mechanical and Solid-State Drives. SATA connectors are made to replace the much older and obsolete IDE or PATA interface which used a much larger connector and ribbon type cable. Thanks to the newer standard implementation at the time, it provided a fixed connector standard and the means to provide larger transfer bandwidth and reduce cable size and cost. SATA interface also provides support for options such as hot-swap, NCQ and AHCI.

The first SATA revision (SATA 1) provided the data transfer bandwidth of up to 150MB/s. SATA II doubled that, providing 300MB/s and the current SATA standard SATA III providing a data transfer capability of up to 600MB/s. Even though these SATA standards are different in data transfer potential, the best part is that these hard drives with this standard are backward compatible and the connectors are standard with a one-sided connector with a right angled-notch.

Before we progress, understand that these numbers are the amount of data in seconds, but the actual performance throughput to take advantage of this bandwidth range depends on the potential of the storage drive and the controller that is responsible for handling SATA.

The emphasis on types of SATA controllers for motherboards is mentioned in the motherboard guide.

SATA Ports

SATA Ports

The explanation of features for SATA are as follows:

Hot Plugging/Hot Swapping is a term used for devices which allows the user to replace the component with another or removing it without shutting down the system or interrupting it (unless a program or data is actively used at the time of removal). Removing USB flash drives is an excellent example. This enables the user to add or remove drives (preferably when not in use) should one require. However, it should be noted that removing the drive with the operating system will interrupt your system. This is useful in cases where you have additional drives where you use it for the purpose of storing data.

Native Command Queuing (NCQ) is a function for SATA that prioritizes read and write instructions on the HDD once it’s done by the user. This works by adjusting its recording head based on where the data is stored or where it needs to be written and reduces the number of rounds it would make by accessing that area of the disk as quick as possible. This reduces the workload on a mechanical drive’s recording head, therefore optimizing it for quicker speed.

NCQ works with SSDs as well. Combined with the natural benefits of an SSD, it helps to provide better performance that one can get from the storage drive especially multi-tasking between storage-intensive tasks.

Advanced Host Controller Interface (AHCI) is a function made by Intel. It allows the functions mentioned above- hot swap and NCQ. It’s a present specification that allows hardware component manufacturers to transfer data from a storage drive to the computer’s memory.

SATA has a separate connector for power. Older Hard drives and even optical drives use Molex connectors, but hard drives have implemented SATA power connector standard for easy connectivity and also to make a hot swap easier especially for NAS units. Modern power supply manufacturers have a set of cables with SATA power connectors where you can simply plug it in. While the SATA power cable from the power supply is connected to the drive, while the SATA cable is connected from the drive to the motherboard’s SATA connector.

  • mSATA

Zotac_ID92_Plus_0067

Mini SATA uses SATA specification but with a much smaller sized connector. This was primarily designed for notebooks, netbooks, laptops, mini-PCs and even for desktop motherboards of all sizes.

  • M.2

M.2 Mount

M.2 Mount

M.2 was originally referred to as Next Generation Form Factor standard. This interface specification is made for slimmer profile add-on cards and for storage. Eventually, M.2 standard replaced mSATA due to the versatility of the standard which allows the user to use the connector for more than just storage, should he choose to do so. Due to a slimmer profile, it can be used in ultrabooks, tablets, mini-PCs and desktop motherboard of all sizes. The current specification provides a bandwidth of up to 10 Gb/s.

As far as desktop motherboards are concerned, usually a motherboard has a single mSATA port, but there have been times when motherboard manufacturers have provided two, with one locked for a specific function. Such as Gigabyte X99-UD4.

M.2 has four lengths which allow more NAND chips to be installed and used. The physical compatibility depends more on the motherboard or the device that has the M.2 port. They are of 30mm, 42mm, 60mm, 80mm and 110mm. The width is always of 22mm. There are threaded mounts along with a screw on the motherboard between these standard lengths so that a user can secure the M.2 drives properly.

Furthermore, there are two types of M.2 sockets- B Key and M Key. A B-Key based M.2 drives use up to 2 PCIe lanes while M-Keys can use up to 4 PCIe lanes. Most M.2 drives and sockets available now have B+M sockets which compatible with both key types.

It should be noted that though almost all mid-end motherboards have one (Z170 provides up to three) M.2 port, there are limited amount of PCIe lanes provided by the chipset. Depending on the cards and drives occupying existing slots and SATA connectors, using an M.2 or a PCIe card may disable certain slots or certain SATA ports. Such instructions are always given in the motherboard manual.

  • PCIe

PCIe Slots

PCIe Slots

Peripheral Component Interconnect Express is designed for add-ons such as graphic cards, sound cards, etc. for desktop motherboards. PCIe is a standard that provides high speed. This is useful for storage-specific cards like RAID cards and even PCIe-based SSD. Solid State Drives can be fast enough that it can be limited by the bandwidth provided by SATA, especially in RAID. Since PCIe provides a lot more bandwidth than SATA (determined by the PCIe generation and the slot type x1, x4, x8 or x1) can provide. Some PCIe SSDs are configured in a way that it runs in RAID mode with a dedicated chip on board a device.

The comparison of different PCIe bandwidth with SATA III are as follows:

Throughput Theoretical Maximum Throughput
SATA III 6.0 Gb/s (750 MB/s)
PCI-E 2.0 x2 8 Gb/s (1 GB/s)
PCI-E 2.0 x4 16 Gb/s (2 GB/s)
PCI-E 3.0 x4 32 Gb/s (4 GB/s)

  • SATA Express

SATA-IO-SATA-Express.jpg

This standard is also called as SATA 3.2 specification. This works by using two SATA ports on the motherboard, along with another connector that provides PCIe bandwidth. This way, SATA Express Solid State drives can benefit from a much higher data transfer speeds. Since it uses two SATA ports, the individual ports can be used for SATA-based drives as well.

  • SFF-8643

The SFF-8643 connector is introduced along with NVMe (Non-Volatile Memory Express) which provides low latency, low CPU consumption, improved parallel I/O and high data throughput compared to SATA and even SAS interface.

Leave a Reply

Your email address will not be published. Required fields are marked *

*