CompTIA®A+ Exam Notes : Identify Common PC Connector Types And Associated Cables

1. PC Hardware

1.3 Identify common PC connector types and associated cables

HDMI: HDMI stands for High-Definition Multimedia Interface, a standard for simultaneously transmitting digital video and audio from a source, such as a computer or TV cable box, to a computer monitor, TV or projector.

HDMI Connector types

HDMI connector types

There are currently five standard connector types available for HDMI cables, namely:

Standard HDMI (HDMI Type A):Standard HDMI Connector Types use a 19 pin configuration, carrying video and audio signals. This connector type is commonly used for a variety of at-home devices like TV's, computers, and video game consoles.

Extended Pin HDMI (HDMI Type B): Extended Pin HDMI Connector Types use an extended 29 pin configuration, carrying video and audio signals. This design is less commonly used.

Mini HDMI (HDMI Type C): Mini HDMI cables use a 19 pin configuration, carrying video and audio signals. This connector type is commonly used for recording devices, tablets, and other small devices.

Micro HDMI (HDMI Type D): Micro HDMI cables provide the same features at the Mini HDMI but uses a smaller 19 pin configuration. This connector type is commonly used for cell phones, small cameras, and other portable devices.

Type E (the Automotive Connection System, chiefly developed for in-vehicle use)

These various HDMI cable connector types are easy enough to identify physically, due to their noticeably different sizes. HDMI connector types A, C and D (standard, mini and micro) will be the only versions generally need.

HDMI Connector types

HDMI Cable Types: In addition to the different types of connectors for HDMI, there are several different types of cables used, depending upon the application The HDMI interface allows a port to send high-resolution digital video, theatre-quality sound and device commands through an HDMI connector and down a single HDMI cord, each designed to support a video resolution and features in the HDMI specification.HDMI cables is that each wire pair is a twisted pair, making them balanced cables. This drastically reduces the signal to noise ratio, allowing for longer cable runs without signal loss.

DisplayPort: It is a digital interface standard produced by the Video Electronics Standards Association (VESA), used for audio and video.

PATA(IDE): Parallel Advanced Technology Attachment (originally called ATA and sometimes known as IDE or ATAPI) was the most dominant desktop computer storage interface from the late 1980s until recently, when the SATA interface took over. PATA hard drives are still being utilized today, especially in external hard drive boxes, but they're becoming rare. Some cheaper high-end server storage devices have also used PATA. Like SCSI, PATA has also gone through many revisions. The most recent version of PATA is UDMA/133 which supports a throughput of 133 MB/s.

PATA(IDE) Connector

Although PATA supports two devices per connector in a master/slave configuration, the performance penalty of sharing a PATA port is severe and not recommended if performance is important to the user. The 40-pin connector and cabling is also extremely wide, which is difficult to use in a high-density environment and tends to block proper airflow. The size of the connector also presents problems for smaller 2.5" hard drives, which require a special shrunken connector.

SATA and ESATA: SATA or Serial ATA, is the standard device for connecting storage media, like hard drives and optical drives, to the motherboard. It replaced the older PATA standard that existed for a considerable length of time. It offers much faster data transfer speeds, of which people can’t seem to get enough. The eSATA, or External SATA, is a standard derivative of SATA, that is meant to be used with external hard drives. So far, there have been two basic versions of SATA, with SATA-150 and SATA-300. The numbers 150 and 300 represent the number of MB/s that the interfaces support. SATA doesn't have any performance problems due to cable/port sharing, but that's because it doesn't permit sharing at all. SATA hard disks may be used for building RAID arrays. Other options are not appropriate SATA cables are long, 7-pin cables. Both ends are flat and thin. One end plugs into a port on the motherboard, usually labeled SATA, and the other into the back of a storage device like a SATA hard drive.

SATA and ESATA Connector

SATA Data Pin out

Pin# Signal Name Signal Description
1 GND Ground
2 A+ Transmit+
3 A- Transmit-
4 GND Ground
5 B- Receive-
6 B+ Receive+
7 GND Ground

eSATA is a variation of the SATA interface that supports external storage devices. It provides a slightly different, more rugged connector.

Because eSATA offers fast transfer rates, it has been a popular external hard drive interface used by video editors, audio producers, and other media professionals. eSATA is one of the fastest interfaces available, it is surpassed by both Thunderbolt (10 Gbps) and Thunderbolt 2.0 (20 Gbps), which are alternatives to eSATA. Unlike Firewire, USB, and Thunderbolt, the eSATA interface does not provide power to connected devices. Therefore, all drives connected through eSATA must include a separate power connector to provide electricity to the device.

SATA is the faster serial version of the original parallel ATA (PATA) interface. Both SATA and PATA are Integrated Drive Electronics (IDE) devices, which means the controller is in the drive, and only a simple circuit is required on the motherboard.

SATA data cable (7-pin):

SATA data cable (7-pin)

Serial ATA (Advanced Technology Attachment) (SATA): SATA is a computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives and optical drives

Serial ATA replaces the older PATA, offering several advantages over the older interface , reduced cable size and cost (seven conductors instead of 40), native hot swapping, faster data transfer through higher signaling rates, and more efficient transfer through an (optional) I/O queuing protocol. SATA host adapters and devices communicate via a high-speed serial cable over two pairs of conductors. To ensure backward compatibility with legacy ATA software and applications, SATA uses the same basic ATA and ATAPI command-set as legacy ATA devices.

External Serial Advanced Technology Attachment or eSATA is an external interface for SATA technologies. It is faster compared to USB 2.0 or 3.0, and suitable for backing up large amounts of data using external hard drive. Even though eSATA is part of the SATA interface specifications, it uses a very different physical connector from the internal SATA connectors. The reason for this is to better shield the high speed serial lines used to transfer the signals from EMI protection. It also provides a 2m overall cable length compared to the 1m for internal cables. As a result the two cable types can not be used interchangeably.

Difference between SATA I, SATA II and SATA III

  • SATA I (revision 1.x) interface, formally known as SATA 1.5Gb/s, is the first generation SATA interface running at 1.5 Gb/s. The bandwidth throughput, which is supported by the interface, is up to 150MB/s.

  • SATA II (revision 2.x) interface, formally known as SATA 3Gb/s, is a second generation SATA interface running at 3.0 Gb/s. The bandwidth throughput, which is supported by the interface, is up to 300MB/s.

  • SATA III (revision 3.x) interface, formally known as SATA 6Gb/s, is a third generation SATA interface running at 6.0Gb/s. The bandwidth throughput, which is supported by the interface, is up to 600MB/s. This interface is backwards compatible with SATA 3 Gb/s interface.

  • SATA II specifications provide backward compatibility to function on SATA I ports. SATA III specifications provide backward compatibility to function on SATA I and SATA II ports. However, the maximum speed of the drive will be slower due to the lower speed limitations of the port.

  • IEEE 1394 cabling uses two cable pairs to transmit and receive data. The additional two pair, if present, carries power to the device.

  • Bluetooth can be used for personal area networking devices like keyboards and headphones.

  • Philips screw driver uses "#" sign before the number, such as #1 to denote the size of the blade. Torx screw driver uses "T" sign before the number.

  • PCIe is most likely to be used with a graphic expansion card because of its high bandwidth.

SATA Power connector (15-pin):The SATA 15-pin power supply connector is one of the standard peripheral power connectors in computers. It's the standard connector for all SATA-based hard drives, SSDs and optical drives. SATA power cables come from the power supply unit. The connector is keyed so that it's not possible to insert it in the wrong orientation without breaking something.

SATA Power connector (15-pin)

SATA Power Pin out

Pin# Signal Name Signal Description
1 V33 3.3v Power
2 V33 3.3v Power
3 V33 3.3v Power, Pre-charge, 2nd mate
4 Ground 1st Mate
5 Ground 2nd Mate
6 Ground 3rd Mate
7 V5 5v Power, pre-charge, 2nd mate
8 V5 5v Power
9 V5 5v Power
9 V5 5v Power
10 Ground 2nd Mate
11 Reserved -
12 Ground 1st Mate
13 V12 12v Power, Pre-charge, 2nd mate
14 V12 12v Power
15 V12 12v Power

Molex: A Molex connector is used to provide power to drives of various types. It has four pins, two of which have power, one 12 V and the other 5 V. These are standard for IDE (PATA) or older SCSI drives. The total power demands are from 5 to 15 watts for IDE and 10 to 40 watts for SCSI.

4/8-pin 12 V: With the introduction of the Pentium 4, the motherboard required more power. Supplemental power connections were provided to the motherboard in 4-, 6- (discussed later in this section), or 8-pin formats. These were in addition to the 20-pin connector (discussed later in this section) that was already provided.

There is a 4-pin square mini version of the ATX connector, which supplies 2 pins with 12 V, and an 8-pin version (two rows) that has four 12 V leads. These connect to other items, like the processor, or other components, like a network card that may need power that exceeds what can be provided with the ATX connection to the board.

PCIe 6/8-pin: PCIe slots also draw more power and require power in addition to the main 20- pin connector (discussed next). These additional connectors can be 6 pins and may also contain an additional 2-pin connector on the side for cases where the connection required is 8-pin.

20-pin: The main ATX connector, referenced earlier, is a 20-pin connector. The four pins carrying power are 3.3 V, 3.3 V, 5 V, and 5 V. This allows the motherboard to pull about 20 to 30 watts.

24-pin: The 24-pin ATX connector is simply the 20-pin connector discussed earlier along with the extra 4-pin connector on the side. This provides the 4 pins carrying power as discussed earlier plus an additional 4 pins with 5 V standby, 12 V, 12 V, and 3.3 V.

SATA Data cable , Power cable and hard disk interface physical map

The figure shows the SATA hard drive with both the DATA and Power cables inserted into SATA connector slots.Typical connection of a hard drive using SATA cables. The red cable is SATA data, and the connector on the right is the power SATA cable. An older power supply might only have a ‘molex’ style power connector and not the SATA one shown above. Most hard drives will have the option for both Molex or SATA power connections, and you can use one or the other as you like. The two different types together look like this:

SATA hard drive with both the DATA and Power cables

Fig: SATA Data cable , Power cable and hard disk interface physical map


When selecting a power supply, two issues become important. You need to supply the total wattage required by all the devices and the motherboard of the PC, and you must ensure that it has the connector types required by your devices.

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