HDMI is the most common display connection today, but sometimes you’ll need to convert HDMI to DisplayPort or vice versa. Unfortunately, getting these two ports to work well together isn’t as straightforward as it should be. This is what you should know.
The adapters are not bi-directional
If you search for HDMI to DisplayPort or DisplayPort to HDMI converters on sites like Amazon, you’ll see that pretty much all of them are marked “one-way.” Missing this specification is the biggest mistake customers often make when looking for a way to convert their signal.
Due to the way the signal must be converted, the adapters work in one direction but not the other. However, many people still assume that any adapter can work both ways. Since HDMI to DisplayPort adapters are cheaper, they’re more likely to find their way into your cart. When you try to use them to go from a DisplayPort PC to an HDMI TV, nothing happens! Avoid that problem by making sure you have the correct adapter for the direction you want to go.
HDMI to DisplayPort adapters are usually active
While this is not always the case, converting the signal from HDMI to DisplayPort often requires an active adapter. In other words, they are adapters that need external power to work. There are now adapters on the market that can do the conversion using a small amount of power from an HDMI port, but the results may not be as reliable depending on factors such as cable length.
BENFEI HDMI to DisplayPort Adapter
The Benfei is inexpensive, supports 4K 60Hz signals, and has many positive reviews from satisfied customers. It’s not the right solution for 4K signals above 60Hz, but for everyone else it’s in the sweet spot.
So if you buy an active adapter, make sure you have a free USB port or wall adapter available.
DisplayPort to HDMI conversion should happen at the source
While you don’t need an active adapter to convert from DisplayPort to HDMI, you may experience problems if the DP adapter isn’t connected directly to the DP output of the computer or other device you want to connect to an HDMI display. For example, you don’t want to use an extension cord and then plug in the converter.
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You should not convert more than once
In almost all cases, converting the signal in either direction only works if you do it once. If you have more than one signal converter in the chain, you will almost certainly end up with no or a confused signal. Conversion is already a delicate process, so as a rule of thumb, keep things as simple as possible, even if it means spending money buying the exact conversion hardware you need.
HDMI pin 18 and DisplayPort pin 20 must be disabled
In a properly made converter, in either direction, one pin on each socket must be disabled. HDMI pin 18 and DisplayPort pin 20 should be absent. These pins usually carry power, and if they are connected in this conversion they can damage the devices involved.
That’s why you should be careful with cheap converters. If any of the plugs on the converter don’t have a missing pin, don’t plug it in!
Conversion to DisplayPort is not a free upgrade
The lowest common denominator device in your conversion chain limits the features, refresh rate, and resolution you can achieve. Just because a converter can, for example, output a DisplayPort 1.4 signal doesn’t mean you can get 4K 120Hz from a 4K 30hz HDMI source!
you get what you pay for
If you’re going from HDMI to DisplayPort, be prepared to pay a bit more to get the right solution. In most cases, this will be to connect something other than a PC to a computer monitor using DisplayPort, so you don’t have a choice if HDMI is the only output from the source device.
If you’re using a laptop, you can often use a USB to HDMI or DisplayPort cable, both of which are fairly affordable. This fixes any problems related to power or bulky adapters. So whenever you have the option of using USB as a signal source, we suggest you use it.
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