104 PCWorld DECEMBER 2019FEATURE HDMI VS. DISPLAYPORT
ARC supports highly compressed 5.1
surround, but uncompressed 5.1 and 7.1
audio, as well as sample rates up to
192kHz/24-bit are now possible via HDMI
2.1’s eARC (enhanced ARC) standard.
DisplayPort 1.4 and greater has no such
issues and can pass uncompressed 7.1,
192Hz/24-bit audio to as many as four
displays should you ever have the need for
such a setup. Previous versions supported this
on only a single display or receiver.HDMI CONNECTORS
HDMI connectors have 19 pins and are most
commonly seen in three sizes: Type A
(standard), Type C (mini), and Type D (micro).
Of these, Type A is what you’ll find on TVs,
Blu-ray players, soundbars, and other large
A/V components; Type C is often found on
smaller devices, such as dash cams; and you’ll
typically encounter Type A on phones and
tablets. A fourth category of HDMI connector,
Type E, is used for automotive applications.
Most HDMI connectors rely on friction
to stay in place, although some vendors
have developed proprietary locking
mechanisms designed to prevent the cable
from pulling loose.Alternatively, use the chart from the HDMI
Forum showing resolutions and their
approximate bandwidth (see ‘HDMI
Bandwidths’ on next page). These correlate
roughly to DisplayPort.HDR SUPPORT ON HDMI
AND DISPLAYPORT
Both standards support HDR (High Dynamic
Range), with its wider brightness and color
gamuts, but HDMI 2.0x only supports static
metadata (HDR10), while HDMI 2.1 and
DisplayPort 1.4a/2.0 both support dynamic
metadata (HDR10+, etc).
Static metadata means TV adjustment-for-
content data is sent once at that start of a
video. Dynamic metadata means adjustment
data is sent throughout the video and allows
finer adjustments. Dolby Vision is embedded
into the older stream protocols and will work
with any recent version of both standards.AUDIO TRANSMISSION ON
HDMI AND DISPLAYPORT
HDMI and DisplayPort handle 192Hz/24-bit
audio, but with HDMI, that’s only over a single
cable connection. That’s fine for high-
resolution audio buffs with an HD audio
player and an A/V receiver. But to pass audio
from a TV tuner or pass it through from a
device attached to the TV to an A/V receiver,
HDMI 1.4 and 2.0 use ARC (Audio Return
Channel), which is limited to two channels of
44.1Hz/16-bit uncompressed audio.The three types of HDMI connectors you’re most
likely to encounter are (from left to right) standard,
mini, and micro. A fourth connector type, for
automotive applications, is not shown here.