Picking the right cable for your gaming monitor sounds trivial until you plug in and discover your 4K 240Hz panel is capped at 120Hz, or your Variable Refresh Rate cuts out mid-session. The connector standard matters more than most builders realize. Here is a practical breakdown of HDMI 2.1 versus DisplayPort 2.1 so you can make the right call before you buy.

The Bandwidth Numbers

Bandwidth is the foundation. Every other feature flows from how much data the interface can push per second.

Standard	Raw Bandwidth	Usable Bandwidth
HDMI 2.0	18 Gbps	~14.4 Gbps
HDMI 2.1	48 Gbps	~42.6 Gbps
DisplayPort 1.4	32.4 Gbps	~25.9 Gbps
DisplayPort 2.0 UHBR10	40 Gbps	~38.7 Gbps
DisplayPort 2.1 UHBR20	80 Gbps	~77.4 Gbps

DisplayPort 2.1 at UHBR20 mode nearly doubles HDMI 2.1’s usable throughput. That gap becomes meaningful the moment you push beyond 4K 144Hz without compression.

Can Both Handle 4K 144Hz and 4K 240Hz?

4K 144Hz: Both HDMI 2.1 and DisplayPort 1.4 (with DSC) can handle this. HDMI 2.1 does it uncompressed. DisplayPort 1.4 needs Display Stream Compression (DSC) to hit 144Hz at 4K with 10-bit color. Practically speaking, DSC is visually lossless at these ratios and most users cannot distinguish it from uncompressed output.

4K 240Hz: This is where things separate. HDMI 2.1 can technically hit 4K 240Hz, but only with DSC enabled and 8-bit color. DisplayPort 2.1 at UHBR20 handles 4K 240Hz uncompressed in 10-bit HDR with room to spare. If you own a monitor like the ASUS ROG Swift PG32UCDM (4K 240Hz OLED), DisplayPort 2.1 is the way to feed it properly.

8K territory: DisplayPort 2.1 can run 8K 60Hz uncompressed. HDMI 2.1 requires DSC for 8K. For most builders this is academic, but it illustrates the headroom gap.

Variable Refresh Rate: FreeSync, G-Sync, and HDMI VRR

Both interfaces support VRR, but the implementation differs.

DisplayPort: G-Sync Compatible and AMD FreeSync are built on VESA Adaptive-Sync, which has been part of the DisplayPort spec since version 1.2a. Support is mature, widely tested, and reliable across virtually every monitor released in the last five years.

HDMI 2.1 VRR: Defined in the HDMI 2.1 specification, VRR over HDMI works well on consoles (PlayStation 5, Xbox Series X) and is supported by recent NVIDIA RTX 40-series and AMD RX 7000-series GPUs. However, monitor support is inconsistent. Some panels certified for FreeSync or G-Sync over DisplayPort do not expose full VRR functionality over HDMI, or they limit the VRR range. Always check the monitor’s spec sheet explicitly for “HDMI VRR” support rather than assuming it carries over.

Console vs PC Use Case

If you are gaming on a PlayStation 5 or Xbox Series X alongside your PC, HDMI 2.1 is necessary. Both consoles output exclusively over HDMI, and you will want HDMI 2.1 to unlock 4K 120Hz, HDR, and VRR on those platforms. A KVM switch or a monitor with both HDMI 2.1 and DisplayPort 2.1 inputs (like the LG 27GR95QE-B or Samsung Odyssey OLED G8) is the practical solution for dual-source setups.

For PC-only gaming, DisplayPort 2.1 is the stronger technical choice in every measurable way.

Cable Quality: Where Builds Actually Go Wrong

This is the part most guides skip. Passive cables work fine at lower resolutions and refresh rates, but high-bandwidth modes are brutally unforgiving of cheap copper.

HDMI 2.1 cables: You need an “Ultra High Speed HDMI” certified cable (labeled 48Gbps). Generic cables marketed as HDMI 2.1 without certification often fail at 4K 120Hz+. Brands like Zeskit and Club3D offer certified options for under $15 at 2m. Do not buy no-name cables for this application.

DisplayPort 2.1 cables: UHBR20 (80Gbps) requires a cable certified for that bandwidth. DisplayPort 2.1 cables are categorized as DP40 (40Gbps, supports UHBR10) or DP80 (80Gbps, supports UHBR20). If you are pairing a GPU with a UHBR20 monitor, buy a DP80 cable. Club3D sells a certified 1m DP80 cable for around $20. At lengths beyond 2m, active cables become necessary to maintain signal integrity.

Quick cable checklist:
- HDMI 2.1 at 4K 120Hz+  → "Ultra High Speed" 48Gbps certified cable
- DisplayPort 1.4 at 4K   → Standard DP 1.4 cable, max ~3m passive
- DisplayPort 2.1 UHBR10  → DP40 certified cable
- DisplayPort 2.1 UHBR20  → DP80 certified cable, keep runs short

GPU Support in 2026

NVIDIA RTX 50-series (Blackwell): Full HDMI 2.1 and DisplayPort 2.1 UHBR20 support. The RTX 5080 and 5090 output DP 2.1 natively.

AMD RX 9000-series (RDNA 4): DisplayPort 2.1 UHBR20 and HDMI 2.1 supported. The RX 9070 XT and RX 9080 both include DP 2.1 outputs.

Intel Arc B580/B770: DisplayPort 2.1 UHBR10 (not UHBR20) and HDMI 2.1. Sufficient for 4K 144Hz but not 4K 240Hz uncompressed.

Always verify which UHBR tier your GPU implements, as the marketing label “DisplayPort 2.1” encompasses both UHBR10 and UHBR20.

Which Should You Choose?

Choose DisplayPort 2.1 if:

Your setup is PC-only
You want 4K 240Hz or higher refresh rates with full color depth
You are planning for next-generation monitors
You want maximum VRR compatibility on PC

Choose HDMI 2.1 if:

You share the monitor with a PS5 or Xbox Series X
Your monitor only has HDMI 2.1 as its high-speed input
You need audio return channel (ARC/eARC) for a sound system

Use both if:

Your monitor has both ports — run your PC on DisplayPort and your console on HDMI 2.1 simultaneously.

The hardware matters less than matching the right cable to the right certified standard. Buy certified cables, verify your GPU’s exact output spec, and check the monitor’s VRR compatibility list before purchasing. The connector debate resolves itself once you treat both standards with the respect their bandwidth demands.