The difference between Display Port and HDMI

DisplayPort is an interface standard without any fee for using. It seems that HDMI and DisplayPort have the same function and with a high speed digital serial links.  


In fact, they are completely different on structure. 

On Physical properties, HDMI and Display Port both are based on same infrastructure and used high-speed low voltage differential signal to transmit data when they run on differential coaxial twisted-pair cable. 

But the similarities end there. Although their standards are very similar from the appearance, a great deal of difference on structure. 


Their difference determines the performance of the link cost, compatibility, robustness and easy execution ability.


HDMI standard defines four types of connectors, A to D. In addition to the Type B, the rest are 19 pin. Type C and D are used for small equipment and portable applications.


Two standard cables are slightly different. 

1. HDMI1.0 to1.3 use four pair shield coaxial on differential coaxial, four single-ended control signal , power supply (+ 5 v) and drain. 

2. HDMI1.4 increased the audio return channels and Ethernet, so the fabric of the signal is different. HDMI1.4 uses four pairs coaxial, one unshielded differential pair, three single-ended signal, power supply (+ 5 v) and drain. This means that, HDMI1.4 and HDMI1.3 use different cables. If using a non HDMI1.4 cable in HDMI1.4 system, the audio return and Ethernet function will be lost. However, all function of HDMI1.3 and other new features of HDMI1.4 (such as 3D) can be kept.

Applications and Application Fields of DVI VGA and HDMI Data Cables

This interface is based on PanalLink (an interface technology created by Silicon Image) and TMDS electrical protocol and works as a basic electrical connection. TMDS(transition minimized differential signaling)is a differential signaling mechanism which can code pixel data and then transmit the data via serial connection. Digital signals created by the video card are coded according to TMDS protocol, then transmitted to the receiver via TMDS channel by the transmitter and finally they reach the digital display equipment after decoding. A DVI display system includes a transmitter and a receiver. The transmitter is the source of signals and can be built in the chip of a video card or attached to the PCB of the video card as an additional chip, while the receiver is an electrical circuit on a display which can receive and decode digital signals as well as transmit them to the display circuit. Through the transmitter and the receiver, the signals sent from the video card turn into images on the display. 


VGA (video graphics array) interface is used to output analog signals on the video card. It is also called D-Sub interface. Though LCD(liquid crystal display) can directly receive digital signals, many low-end products still adopt VGA interface in order to match VGA-interfaced video card. VGA is a type D interface with fifteen pinholes in three rows. And there are five pinholes in each row. VGA is the most widely used interface type on video cards. The majority of video cards have this interface. 


HDMI (high-definition multimedia interface) is a brand new interface that transcends those audio-video splitting transmission interfaces of the past. Its transmission rate can reach a maximum of 5Gb/s. Besides,this interface can transmit image data and further more, it can simultaneously transmit audio signals up to eight sound channels. This non-compressed digital data transmission can effectively reduce signal interference and attenuation caused by data type conversion. 

Thick or Thin What is better for HDMI cable?

Firstly. We can not give a directly answer for this question. Because some bad businessman, they will use a thick layer to cover the copper, and make it looks thicker. In fact, what is working is the matter about the thickness of the copper cable inside. It can not see different from surface.While the performance requirements.the thickness of the inside cable of HDMI depends on what AWG you use.and how to choose, it also depends on the length of the HDMI cable in most cases.


There are many model for the cables, like 32#30#28#26#(also called:32AWG,30AWG,28AWG,26AWG)。VB.

Under 5M HD HDMI cable, we suggest you that use the standard 28AWG cable.


It is enough to meet your demand for HD horizon.Between 10-15 M should use 26AWG one.Otherwise it can not guarantee the quality of signal transmission.Over 15 meters need 24AWG wire, prevent the transmission attenuation of signal, a long HDMI line with the chip would increase the transmission distance.

How to identify a excellent headphone

An excellent headphone can’t be decided whether is good or not by the external factor. Not represented by a kind of material and structure. It is perfect match under a modern electro acoustics, materials science, ergonomics and stereo aesthetic. ——《The evaluation of the headset》

The conclusion for an excellent headphone is coming from the objective testing and subjective of listen the music. The objective testing included curve frequency response, response curve, impedance curve, square wave test, intermediation distortion and so on.

The first we need to know the headphone is the characteristic of the headphone’s sound. The advantage of the headphone is small phase distortion, wide frequency response.

The first characteristic is head shadow effect:
What acoustic environment the headphone made is the nature cannot achieve, The waves of sound Nature are interacting with a person's head and ears before enter into the ear canal.  While most record is made for sound playback, audio and video on the two speakers even wiring due to these two reasons we use headphones will feel audio-visual form in the header, listening is not natural, easy to cause fatigue. Head shadow effect can be improved through the use of special physical structure; sound field simulation software and hardware in the market.

The second characteristic is Earphone of low frequency:
Under the low frequency section (40 hz - 20 hz) and ultra-low frequency (20 hz) is through the body of perception, the human ear is not sensitive to the spectrum. Headphones can perfect the replay this low frequency, but because the body cannot feel low frequency, can let a person feel the headset of low frequency. Intermediate frequency for the headset is a sensitive area, the music of the most abundant information, is also the most sensitive to the human ear.The design of the headset to treat intermediate frequency is cautious, some low-grade headphones its frequency response range is limited, but on the mention of intermediate frequency and low get bright and sharp tone and turbidity, powerful voice, caused the appearance of high frequency is good, long time listening to the headphones, will feel dull.

Good headphones sound should have the following features:
1. Bottom and pure, without any unpleasant "slash", "om", sound.
2. Good sense of balance, tone won’t too bright or too dark, however, low frequency energy distribution uniformity, high band fusion between natural and smooth, no abrupt and burr.
3. High frequency extension is good, exquisite and smooth.
4. Low frequency pe deep, clean, full, full of elasticity and strength, no fat and slow.
5. Intermediate frequency distortion tiny, transparent and warm, human kind nature, thickness, magnetic, literally dental and twang.
6. Good resolving power, rich details, small signal can also clear replay.
7. Has a good ability of acoustic field depicting sound field is open, the instrument is accurate, and stable and sound field in enough amount of information, and you won't feel empty.
8. There was no obvious compression, dynamic has a good sense of speed, no distortion or distortion under the volume is small.

Such a headset can perfect replay any type of music, and music have good like real degree, long-term use does not cause fatigue, can make the listener immersed in music.

How to choose Bluetooth earphone?

1. How do I choose a Bluetooth headset?




At first, choose the mono or stereo you need,  if stereo pls check whether your mobile phone support it .  

Second, there generally have many wearing styles such as earbud, ear hook, head-loading, clothespin-type, etc., you can choose one style according your needs.

2.What is the effective range of Bluetooth?




Bluetooth is a protocol for short-distance data communications and applications, the nominal effective range is 10 meters, the original product's is 7-8 m,  high imitation product's  is 2-6 m. Signal is impacted by the  environment. Generally without noise if there is no obstructions between the headphone and mobile phone within 3 meters.

(Ps: it will have noises if putting some kinds of phones and earphones on different sides of his body.)


3.Whether Bluetooth headset battery can be changed, how about its life expectancy?




Most Bluetooth headset battery is built-in lithium battery,  which can not be replaced, every new battery can charge about 500 times. According it can use 3 days after per charging , 500 times charging can use 1500 days, that is around 2-3 years. A bluetooth can also be eliminated after use for two years, so it is not necessary to worry about the problem of bluetooth headphone battery failure.

HDMI High Definition Oxygen-free copper wire

HDMI High Definition Oxygen-free copper wire
4N Oxygen-free copper material
4N Oxygen-free copper is high purity Oxygen-free copper, the material is free of Oxygen, also is free of deoxidizer residual copper ( Actually it is still has some micro-oxygen and some impurities ), the content of oxygen not more than 0.03%, total impurities not more than 0.05%, copper purity more than 99.95% based on the standard. According to the actual data test, the high purity Oxygen-free copper shows more delicate in display when compare with normal purity copper, it is not easy oxidation, can be used in every place, noise reduction, the capacity of keeping real color is better than purity copper. Therefore, 6N Oxygen-free copper is better than 4N Oxygen-free copper.

FAQ about DVI,VGA Cables

1.What cables should I use for home audio devices under the environment of the current market?

HDMI 1.4V is enough for routine using and HDMI 2.OV is required for the current newly 4K.


2.What’s the English code of CCS、BC、CCA that shows on your specification?

They mean the quality and structure of cables. Copper-Clad Steel for CCS, 

Bare Copper for BC and Copper-Clad Aluminum for CCA.


3. I have bought DVI 24+5 from VCOM, but it can’t be plugged into the DVI port of my motherboard, may I know what’s the problem?

Pls make sure the port of motherboard is 24+5, if not, it definitely can’t be plugged into.


4. If I need 50M VGA cables for my engineer project, can VCOM brand 50m VGA cables work as usual?

Yes, of course.


5. Which is better for VGA cables of 3+4、3+6、3+8?

3+8 is the best, and then 3+6, and 3+4 is the last choose.


6. Why the screen was so fuzzy after the displayer connected with VGA cable?

Pls adjust the screen resolution to the best if it was short length VGA cable.

If you used long meter VGA, it is normal to have slightly fuzzy, trailing, ghost because this is the common problem of analog signal. 


7. I have bought a DVI cable and there was no image after I connected to the PC mainboard. What’s wrong?

Pls plug the DVI cable into the DVI interface of PC discrete graphics and adjust the display signal to DVI.


1. I bought an HDMI cable, when connecting the PC motherboard port, no display, why?

Please plug the HDMI cable to the PC discrete graphics HDMI connector, and adjust the monitor signal source to HDMI.


2. I bought a DP cable, when connecting the PC motherboard port, no display, why?

Please plug DP line to PC discrete graphics DP connector, and adjust the monitor signal source to DP.


3. There are three colors on my motherboard USB ports, black, blue and blue-green, what are those ports?

Black: USB2.0; Blue USB3.0; Blue-green:USB3.1


4. Can the DVI and VGA be transformed?

Yes, but only DVI-I can.


5. Nowadays, why there is no standard VGA interface on the graphics card?

VGA port is an analog signal, nowadays it’s the time pursue for screen Sharpness, VGA has gradually been replaced by other more high-end digital port.


6. My monitor only has VGA port, but graphics card has no VGA, how can I make it work?

You need a converter cable.


7. I see VCOM has HDMI AM TO CM cable, what kinds of equipment usually use these cables? If I have bulk purchasing, who do I sell to?

HDMI C interfaces mainly use in digital cameras and notebooks and a few discrete graphics.



8. Why nowadays only has HDMI interface on TV?

HDMI interface is Hitachi, Panasonic, Philips, Silicon Image, Sony, Thomson and Toshiba 7 companies jointly launched, because of the strength of promoters, and earlier launch time determines the HDMI’s popularization.

Why there is no image on display monitor after connect to 1.4V HDMI cable

Firstly ensure that transmits image resolution & refresh rate are not higher than 3840*2160@30Hz/1920*1080@60Hz and the display adapter driver is correct , the display is open with HDMI signal source.
Secondly please connect the HDMI cable to the discrete graphics(if any) HDMI interface, if without discrete graphics, please replace other brand HDMI cable to operate under the same configuration. If it still doesn't work, please try to change the display.
All of the above, If this does not resolve your problem, please contact to get professional advice.

Why there is only image output no audio output after connect to HDMI cable

Firstly please make sure that it is buildt in Speaker type display and the HDMI cable connect to the audio & video output interface correctly.
Secondly make sure that the display adapter driver is correct, and then you need to set the audio output as the HDMI output signal.
All of the above, If this does not resolve your problem, please contact to get professional advice.

Why the monitor will become splash screen and video corruption after connecting the HDMI cable?

What does the HDMI version mean?

In the past the HDMI version number (for instance 1.3b or 1.4a) was used to mark cable products. This is not allowed any more because often suppliers marked products with wrong HDMI versions. The result was that customers often bought products in the believe that certain HDMI features are supported which was not always the case.
HDMI cables are only produced according to the following 4 HDMI cable specifications:
    • HDMI
    • Highspeed HDMI
    • HDMI with Ethernet
    • Highspeed HDMI with Ethernet
Please note that the a.m. HDMI cable specifications do not guarantee that a specific HDMI version is supported by every HDMI cable supplier/ trader. With KabelDirekt HDMI cables you are on the safe side that always the newest HDMI version is supported.
KabelDirekt HDMI cables are produced according to the standard Highspeed HDMI with Ethernet and are fully compatible with HDMI 2.0 (all available HDMI features as well as resolutions up to 4K in 3D are supported). The bandwidth of KabelDirekt HDMI cables is 18,2 GigaBit/ second.

What is HDMI 2.0b

HDMI 2.0b is backwards compatible with earlier versions of the HDMI specification and the most recent update of the HDMI specification. Also enables key enhancements to support market requirements for enhancing the consumer video and audio experience.
What are the key advanced features enabled by HDMI 2.0b?
•Simultaneous delivery of dual video streams to multiple users on the same screen
•Simultaneous delivery of multi-stream audio to multiple users (Up to 4)
•Enables transmission of High Dynamic Range (HDR) video
•CEC extensions provide more expanded command and control of consumer electronics devices through a single control point
•Bandwidth up to 18Gbps
•4K@50/60 (2160p), which is 4 times the clarity of 1080p/60 video resolution
•Up to 32 audio channels for a multi-dimensional immersive audio experience
•Up to 1536kHz audio sample frequency for the highest audio fidelity
•Support for the wide angle theatrical 21:9 video aspect ratio
•Dynamic synchronization of video and audio streams
Current High Speed cables (Category 2 cables) are capable of carrying the increased bandwidth. HDMI 2.0b does not define new cables or new connectors. 

What's new in HDMI 2.0

2.0 Version increases bandwidth to 18Gbps significantly. Also includes the following advanced features:
•Up to 1536kHz audio sample frequency for the highest audio fidelity
•Up to 32 audio channels for multi-dimensional immersive audio experience
•Resolutions: Up to 4K@50/60 (2160p), 4 times the clarity of 1080p/60 video resolution, for the ultimate video experience
•Dynamic synchronization of video and audio streams
•Support for the wide angle theatrical 21:9 video aspect ratio
•Simultaneous delivery of multi-stream audio to multiple users (Up to 4)
•Simultaneous delivery of dual video streams to multiple users on the same screen
•CEC extension provide more expanded command to control consumer electronics devices through a single control point

Host USB-C Port Capability: Power, Data, and Video

Some computers such as the Lenovo Yoga 910 have more than one USB-C port and they have different functions. The picture below shows that one USB-C port (left) is a charging only port while the other USB-C port (right) supports video and data. Please make sure to plug in your USB-C adapter or docking station to the right USB-C port.
Some USB-C ports have the Thunderbolt technology built in to achieve all features offered by USB-C as well as higher data transfer rate and additional features offered by the Thunderbolt technology. Thunderbolt 3 ports support data, video and charging and usually have the Thunderbolt logo printed next to them. Below picture shows a Thunderbolt enabled USB-C port.
Below picture shows two USB-C ports on a Windows laptop. One USB-C port (left) supports Thunderbolt 3 and therefore offers the video, data, and charging capability. The other USB-C port (right) only supports data and charging without video capability. Please make sure to connect your USB-C / Thunderbolt 3 adapters and docks to the Thunderbolt 3 port on your laptop.
USB-C adapters and docks will work fine when plugged into a Thunderbolt 3 port on a laptop. However Thunderbolt 3 adapter and docks will not work when plugged into a USB-C port without the Thunderbolt capability. Refer to the article below for the list by manufacturer of computers that support Thunderbolt 3. Please contact the laptop manufacturer directly if you are not sure what kind of USB-C port your laptop has.

List of Devices Supporting Video & Power over USB-C

Not all USB-C ports support all features of USB-C. Some computers and smartphones support data only for flash drives while some others support video out and power as well.
Here is the list by manufacturer of computers and smartphones that support full feature USB-C:
Dell XPS 12 9250, 13 9350 / 9360 / 9365 / 9370, 15 9550 / 9560 / 9570 / 9575, Latitude 5290 / 5480 / 5580 / 7275 / 7280 / 7285 / 7290 / 7370 / 7380 / 7390 / 7480 / 7490 / 7520 / 7720 / E5570, Precision (certain configurations) 3520 / 15 3510 / 5510 / 5520 / M7510, 17 M7710, Alienware 13 / 15 / 17
2016 / 2017 / 2018 MacBook, MacBook Pro, iMac, iMac Pro
Aspire Switch 12 S / R13, V15 / V17 Nitro, TravelMate P648, Predator 15 / 17 / 17X, Chromebook R 13
ROG GL / G5 / G7 / GX / Strix, ZenBook Pro UX501VW, ZenBook 3 Deluxe / Pro, Transformer 3 Pro, Schenker XMG, Q524UQ 2-in-1 15.6, Chromebook Flip C302
Aorus X5 15, X7 DT 17, BRIX / BRIX S
SC15 / SC17 Geforce GTX 1060
Pixelbook / Pixelbook 2
Elite X2 1012 G1 / G2, Z1 Workstation G3, Spectre 13.3 / x360, EliteBook 1040 G4 / X360 G2 / X 360 1020 G2 / Folio G1, ZBook 17 G3 / 17 G4 / 15 G3 / 15 G4 / Studio G3 / Studio G4 / Z2 G4 / Z4 G4 / Z6 G4 / Z8 G4, Chromebook 13 G1
Legion Y720, IdeaPad Y900, Miix 720, Thinkpad P 50/70, T 470 / 470S / 570, X270, X1 Carbon, X1 Yoga, Yoga 370 / 900 / 910, P50 / P51 / P51S / P70 / P71
Phantom / Phantom Pro, Ghost / Ghost Pro, Stealth / Stealth Pro, Titan / Titan Pro, Dominator / Dominator Pro, Vortex G65
Blade / Stealth / Pro
NP900X5N, Notebook Odyssey, Notebook 9 15 Inch, Galaxy Note 9 / Note 8 / S9 / S9+ / S8 / S8+
HTC 10 / U11 / U12
Gram 15Z970, LG G5 / V20 / V30
Portege X20W / X20E / X30 / X30-E, Tecra X40 / X40E
P 750DM / 770DM / 870DM
Workstation CELSIUS H760
Surface Book 2, Surface Go, Lumia 950 / 950 XL
ZBOX / MI549 / MI552 / MI572 / MI553
MateBook X Pro

Types of USB Connectors

USB connector types multiplied as the specification progressed. The original USB specification detailed Type-A and Type-B plugs and receptacles. The USB Type-C Specification defines a new small reversible-plug connector for USB devices. The Type-C plug connects to both hosts and devices, replacing various Type-A and Type-B connectors and cables.

USB development history& Transfer Rates

What is Alternate Modes?

For the first time, the USB-IF has allowed alternate protocols on their connectors to extend the capabilities of this connection. The addition of non-USB formats like DisplayPort, Thunderbolt 3, and MHL will allow devices to connect to displays and transfer data at higher speeds through a single USB-C cable. For example, Thunderbolt 3 can allow for bandwidth up to 40Gbps and support dual 4k displays @ 60Hz. This allows for ultra-fast data transfer to and from a Hard Drive or support for the latest TVs and monitors all in a compact adapter.
Not all USB Type-C cables or devices are capable of supporting these technologies. Always consult the specifications for your devices to confirm support for alternate modes. As an example, some laptops support Type-C but do not support Thunderbolt 3 or alternate modes. Computers and smartphones with USB-C 2.0 will not support alternate modes and thus, are not capable of transmitting video.

What is Power Delivery?

The addition of the power delivery capability to USB Type-C effectively reduces the clutter of having to carry multiple cables and adapters for power, A/V, and data transfer. This additional specification allows for a theoretical 100W max charging power, which is sufficient to charge devices larger than tablets such as laptops. Power Delivery is in its infancy but will become more widely adopted as device manufactures and connectivity providers develop the technology. Not all USB-C cables or devices are capable of supporting USB PD. Always consult the specifications for your devices to confirm support for the PD (as well as the maxium charging power).

                              Table 2-1 USB Type-C Specification Release 1.3

Mode of Operation Nominal Voltage Maximum Current
USB 2.0 5V 500 mA
USB 3.1 5V 900 mA
USB BC 1.2 5V Up to 1.5A
USB Type-C 5V 1.5A or 3A
USB PD Configurable up to 20V Configurable Up to 5A