What is USB Type-C™ ?

USB Type-C™ is the new USB plug and port connection developed by the USB Implementers’ Forum (USB-IF) which is the governing body for USB technology. It seeks to replace the USB Type-A and USB Type-B found on most computing devices with a versatile, smaller, and reversible connection.
The underlying technology of this new connection is designed to support faster data transfer rates (up to 20Gbps), more charging power (up to 100W), and video / audio capability through alternate mode. USB Type-C can support alternate display protocols such as DisplayPort™, Thunderbolt™ 3, and MHL™.
Devices that will support USB Type-C range from notebooks and smartphones to external Hard Drives and audio equipment. The shift in technology is in part motivated by the preference for devices to be more compact yet more capable then they have previously been, a capability not easily achieved with a technology that is over 16 years old.

DP/MDP Passive and Active Dongle

DP/MDP Passive Dongle can provide Dual Mode signal in DP port
DP/MDP Active Dongle only can provide DP signal in DP port
DP Connector can provide Dual mode signal that means the DVI 
HDMI signal output can be exchanged by Passive dongle
DP Connector only can provide DP signal means the DVI HDMI 
signal output can be exchanged by Active dongle only
The example for AMD 5870 MDPx6
If need 3DVI display output
It needs 2PCS Passive Dongle + 1PC Active Dongle (As GPU only 
support 2 DUAL MODE signal)
If need 6DVI display output
It needs 2PCS Passive Dongle + 4PCS Active Dongle (As GPU only 
support 2 DUAL MODE signal)

What does “UHD” mean? What is the difference between “UHD” and “FHD”?

“UHD” is the abbreviation of Ultra High Definition, which means Ultra High Definition. The “UHD” standard proposal issued by the International Telecommunication Union (ITU) calls the display with a physical resolution of 3840×2160 (4K×2K) and above as ultra high definition. Under different standards, the resolution represented by UHD is different. For example, the common resolution of Full Aperture UHD in the film industry is 4096 x 3112 and Academy UHD is 3656×2664. Generally speaking, UHD TV is the standard issued by ITU.

FHD is called Full High Definition. In the internationally recognized standards, “HD” is defined as three standard forms of 720p, 1080i and 1080p. But FHD is 1920*1080p. There are two conditions for this standard: 1. the video vertical resolution exceeds 720p or 1080i; 2. the video aspect ratio is 16:9. “P” means progressive scanning and “I” means interlaced scanning. Generally speaking, 480*320, 640*480 are “standard definition”; 1024*720p, 1920*1080i are “high definition”; 1920*1080p is “full HD”; 3840*2160, 7680*4320 are “ultra HD” (UHD).

Then we can clearly see the difference between UHD and FHD. UHD is Ultra High Definition with a resolution of 3840×2160 and above and FHD is 1920×1080p. In terms of video resolution, UHD is at least 4 times higher than FHD. The previous difference is intuitive and can be distinguished with our eyes.
HD 1280*720
FHD 1920*1080
QHD 2560*1440
UHD 3840x2160 (4K)
WFHD 2560*1080
WQHD 3440*1440
WUHD 5120*2160