A DisplayPort to HDMI cable works one-way — from a DisplayPort source (like a GPU) to an HDMI display — but only if your source supports Dual-Mode DisplayPort (DP++).
- Your GPU or Thunderbolt port supports DP++ (most modern NVIDIA/AMD cards do)
- You’re going DP source → HDMI display, not the reverse
- Cable or adapter bandwidth matches your target resolution (e.g., 4K@60Hz needs HDMI 2.0)
- You’re connecting an HDMI source to a DisplayPort display — that’s the wrong direction
- Your source doesn’t support DP++ and you’re using a passive cable
- You’re trying to push 4K@60Hz through an old HDMI 1.4 display
Why Direction Matters
DisplayPort and HDMI are not interchangeable signals. A passive DisplayPort to HDMI cable relies on your source outputting a translated signal — that’s what DP++ does. Without it, a passive cable produces no picture at all. Plugging it in backwards (HDMI device into a DisplayPort monitor) simply won’t work with a passive cable either.
If your source lacks DP++, you need an active adapter with its own conversion chip. Active adapters work regardless of DP++ support but cost a little more.
Resolution and Refresh Rate Limits
Even when the cable works, your resolution ceiling depends on both ends. Check the table below for common combinations.
| Setup | Works? | Need | Note |
|---|---|---|---|
| DP 1.2 → HDMI 1.4 display | Yes | DP++ source, passive cable | Up to 4K@30Hz |
| DP 1.4 → HDMI 2.0 display | Yes | DP++ source, quality passive cable | Up to 4K@60Hz |
| DP 1.4 → HDMI 1.4 display | Partial | DP++ source | Capped at HDMI 1.4 limits |
| HDMI source → DP display | No | Powered active converter | Passive cable won’t work |
| DP source, no DP++ → HDMI display | No | Active adapter | Passive cable won’t work |
How to Check for DP++ Support
Most discrete NVIDIA and AMD GPUs made after 2012 support DP++. Check your GPU’s spec sheet or look for a small DP++ logo next to the port. Thunderbolt ports on laptops also typically include DP++ support. If you’re unsure, an active adapter is the safe choice — it works with or without DP++.
For more on USB-C video output compatibility, see our guide on whether USB-C supports video, since many modern laptops use USB-C with DisplayPort Alt Mode instead of a full-size DP port.
Passive vs. Active: Which Should You Buy?
- Passive cable/adapter — cheaper, no power needed, works if source has DP++
- Active adapter — works without DP++, handles longer cable runs, costs more
Cable quality also matters. Cheap cables can drop signal at 4K. Look for cables rated for the HDMI version you need. The VESA DisplayPort 2.1 specification outlines the full bandwidth capabilities if you want to dig into the technical details.
If you’re running into a blank screen, check our troubleshooting guide on why USB-C to HDMI isn’t working — many of the same causes apply to DisplayPort setups too.
Bottom line: A DisplayPort to HDMI cable is a reliable, low-cost solution for connecting a PC GPU to an HDMI monitor — as long as you’re going in the right direction and your source supports DP++. When in doubt, spend a few dollars more on an active adapter and skip the guesswork.