Quick Answer

For 4K 240Hz gaming on a PC, DisplayPort 2.1a UHBR20 is the correct choice, providing up to 80 Gbps of bandwidth for uncompressed 4K 240Hz output. HDMI 2.1 tops out at 48 Gbps, which supports 4K at 144Hz uncompressed or 4K at 240Hz only with Display Stream Compression. HDMI is the better choice for connecting a PS5 or Xbox Series X.

The Bandwidth Numbers Behind Each Standard 🔧

DisplayPort 2.1a UHBR20 delivers 77.4 Gbps of usable throughput after encoding overhead. HDMI 2.1 delivers 42.6 Gbps of usable throughput. Uncompressed 4K at 240Hz at 8-bit colour with no chroma subsampling requires approximately 63 Gbps. This means DP 2.1a UHBR20 clears the threshold without compression, while HDMI 2.1 falls short by around 20 Gbps. HDMI 2.1 can carry 4K at 240Hz using Display Stream Compression, which is visually lossless, but it does require the compression codec to be active. For pure signal fidelity, DisplayPort 2.1a is the technically superior connection for 4K 240Hz.

Practical Setup Differences for SA Gamers 🎮

For a PC gaming setup, use DisplayPort 2.1a from your GPU to the monitor. Most RTX 50-series and RX 9000-series GPUs include DP 2.1a outputs. Use HDMI 2.1 from a console to the monitor's HDMI port if the panel includes dual inputs. Many 4K 240Hz monitors now include two HDMI 2.1 ports alongside one or two DisplayPort 2.1a ports, allowing a multi-device desk setup without a switch. For SA buyers connecting a PS5 for family or social gaming alongside a PC, this dual-port setup eliminates the need for a separate TV or KVM switch.

Cables: What to Buy and What to Avoid 💡

For DisplayPort 2.1a UHBR20 speeds, purchase a cable explicitly certified for UHBR20 or 80 Gbps throughput. Standard DP 1.4 cables have the same physical connector but cannot carry UHBR20 signal speeds and will force a lower link rate fallback. Passive UHBR20 cables are practical at lengths of 1m to 1.5m; beyond 2m, active optical cables are required and significantly more expensive. For HDMI 2.1, use a certified Ultra High Speed HDMI cable rated to 48 Gbps. These are widely available locally and are more forgiving of cable length than DP 2.1a, with passive cables reliably working at 2m and certified cables available at 3m.

TIP

Check the Port Label on Your Monitor ⚡

Not every DisplayPort on a 4K 240Hz monitor is DP 2.1a. Many models include one DP 2.1a port and additional DP 1.4 ports for multi-monitor daisy-chaining. The primary DP port for maximum bandwidth is usually labelled DP 2.1 or marked as the main input in the monitor's spec sheet. Plugging into a DP 1.4 port limits you to 144Hz or forces DSC engagement.

FAQ

Can I use a USB-C to DisplayPort 2.1a cable for 4K 240Hz?

Only if the USB-C port on your GPU or laptop outputs DisplayPort 2.1a Alt Mode at UHBR20 speeds. Most USB-C ports on current laptops are limited to DP 1.4 or Thunderbolt 4 (which tops out at UHBR10). Desktop GPU USB-C ports vary by model, so check your GPU's specification sheet.

Does HDMI 2.1 support adaptive sync (VRR) for gaming?

Yes. HDMI 2.1 includes Variable Refresh Rate (VRR) as part of its specification. It works with both G-Sync Compatible and FreeSync monitors over HDMI on supported devices. However, the VRR range over HDMI may differ from the monitor's rated VRR range over DisplayPort on some models.

Is DisplayPort 2.1a widely available on monitors sold in SA?

Yes, from 2025 onward, flagship 4K 240Hz monitors from ASUS, LG, and Samsung sold locally include DP 2.1a inputs. Mid-range 4K monitors at 144Hz to 160Hz still commonly use DP 1.4 with DSC, which is entirely adequate for those refresh rates.

Building a 4K 240Hz PC or console setup? Evetech stocks 4K 240Hz monitors with DisplayPort 2.1a and HDMI 2.1 inputs, alongside RTX 50-series GPUs to drive them. Browse the Evetech monitor and GPU sections to configure your bandwidth-ready display stack.