DisplayPort vs HDMI 2.1: Raw Bandwidth Compared

When comparing the maximum uncompressed raw bandwidth throughput of DisplayPort to HDMI 2.1, the outcome depends on the generation of DisplayPort being referenced. HDMI 2.1 delivers a fixed maximum raw bandwidth of 48 Gbps, outperforming older standards like DisplayPort 1.4, which caps at 32.4 Gbps. However, the newer DisplayPort 2.1 standard surpasses HDMI 2.1 substantially, reaching up to 80 Gbps of raw bandwidth at its highest transmission tier.

HDMI 2.1 Bandwidth Capabilities

HDMI 2.1 utilizes Fixed Rate Link (FRL) signaling across four lanes, with each lane operating at up to 12 Gbps. This yields a total maximum uncompressed raw bandwidth of 48 Gbps. Because HDMI 2.1 uses a 16b/18b line coding scheme, approximately 11.1% of that bandwidth is reserved for transmission overhead. As a result, the maximum usable uncompressed data throughput for video and audio payloads is roughly 42.66 Gbps.

DisplayPort 2.1 Bandwidth Capabilities

DisplayPort 2.1 introduces the Ultra-High Bit Rate (UHBR) transmission standards, operating over four lanes with more efficient 128b/132b channel encoding (under 3% transmission overhead). DisplayPort 2.1 features three distinct speed tiers:

  • UHBR 10: 10 Gbps per lane, resulting in 40 Gbps of raw bandwidth (38.69 Gbps effective data rate).
  • UHBR 13.5: 13.5 Gbps per lane, resulting in 54 Gbps of raw bandwidth (52.22 Gbps effective data rate).
  • UHBR 20: 20 Gbps per lane, resulting in 80 Gbps of raw bandwidth (77.37 Gbps effective data rate).

DisplayPort 1.4 Context

DisplayPort 1.4 remains widely deployed on modern monitors and graphics cards. It operates over High Bit Rate 3 (HBR3) across four lanes at 8.1 Gbps per lane, offering a maximum raw bandwidth of 32.4 Gbps. Using the older 8b/10b encoding scheme (20% overhead), the maximum uncompressed data throughput is limited to 25.92 Gbps. Against DP 1.4, HDMI 2.1 provides roughly 48% more raw bandwidth and 64% more effective data payload.

Direct Comparison Summary

  • DisplayPort 1.4: 32.4 Gbps raw (25.92 Gbps effective)
  • HDMI 2.1: 48.0 Gbps raw (42.66 Gbps effective)
  • DisplayPort 2.1 (UHBR 10): 40.0 Gbps raw (38.69 Gbps effective)
  • DisplayPort 2.1 (UHBR 13.5): 54.0 Gbps raw (52.22 Gbps effective)
  • DisplayPort 2.1 (UHBR 20): 80.0 Gbps raw (77.37 Gbps effective)

At peak specifications, DisplayPort 2.1 UHBR 20 exceeds HDMI 2.1's raw bandwidth throughput by 32 Gbps—a 66.7% increase. Combined with its lower encoding overhead, DisplayPort 2.1 allows native, uncompressed 4K at 240 Hz or 8K at 60 Hz with 10-bit color, whereas HDMI 2.1 must rely on Display Stream Compression (DSC) or chroma subsampling to achieve equivalent high-end display configurations.