HomeThunderbolt 4 and USB4
Thunderbolt 4 and USB4 bandwidth
Thunderbolt 4 / USB4 40 Gbps is rated 40 Gbps and carries 25.92 Gbps of video per display, the limit of the DisplayPort stream it tunnels. At 8-bit without compression it carries 1080p up to 406 Hz, 1440p up to 251 Hz, 3440x1440 up to 193 Hz and 4K up to 120 Hz.
Thunderbolt 4 / USB4 40 Gbps carries DSC, so modes over its payload can still fit when both ends support it.
Thunderbolt 4 / USB4 40 Gbps is assumed to tunnel DisplayPort 1.4a (HBR3), which only a secondary source (Wikipedia) states.
Highest refresh rate on Thunderbolt 4 / USB4 40 Gbps
| Resolution | 8-bit | 10-bit | 10-bit with DSC (theoretical maximum at 8 bpp) |
|---|---|---|---|
| 1080p (1920x1080) | 406 Hz | 337 Hz | 874 Hz |
| 1440p (2560x1440) | 251 Hz | 205 Hz | 601 Hz |
| 3440x1440 (3440x1440) | 193 Hz | 158 Hz | 484 Hz |
| 4K (3840x2160) | 120 Hz | 97 Hz | 318 Hz |
| 5K (5120x2880) | 69 Hz | 56 Hz | 192 Hz |
| 8K (7680x4320) | 31 Hz | 25 Hz | 90 Hz |
Thunderbolt 3
Thunderbolt 3 is rated 40 Gbps and carries 17.28 Gbps of video per display, the limit of the DisplayPort stream it tunnels. At 8-bit without compression it carries 1080p up to 288 Hz, 1440p up to 174 Hz, 3440x1440 up to 133 Hz and 4K up to 81 Hz.
Thunderbolt 3 is assumed to tunnel DisplayPort 1.2 (HBR2), because no public source states the version.
| Resolution | 8-bit | 10-bit |
|---|---|---|
| 1080p (1920x1080) | 288 Hz | 237 Hz |
| 1440p (2560x1440) | 174 Hz | 141 Hz |
| 3440x1440 (3440x1440) | 133 Hz | 107 Hz |
| 4K (3840x2160) | 81 Hz | 65 Hz |
| 5K (5120x2880) | 47 Hz | 37 Hz |
| 8K (7680x4320) | under 24 Hz | under 24 Hz |
Popular modes on Thunderbolt 4 / USB4 40 Gbps
| Mode | 8-bit | 10-bit |
|---|---|---|
| 4K 60Hz | Pass, 12.54 Gbps | Pass, 15.68 Gbps |
| 4K 120Hz | Tight, 25.82 Gbps | Needs DSC, about 1.3:1 |
| 4K 144Hz | Needs DSC, about 1.3:1 | Needs DSC, about 1.6:1 |
| 4K 160Hz | Needs DSC, about 1.4:1 | Needs DSC, about 1.8:1 |
| 4K 165Hz | Needs DSC, about 1.5:1 | Needs DSC, about 1.8:1 |
| 4K 240Hz | Needs DSC, about 2.2:1 | Needs DSC, about 2.8:1 |
| 1440p 144Hz | Pass, 14.08 Gbps | Pass, 17.60 Gbps |
| 1440p 165Hz | Pass, 16.30 Gbps | Pass, 20.37 Gbps |
| 1440p 240Hz | Pass, 24.62 Gbps | Needs DSC, about 1.3:1 |
| 1440p 360Hz | Needs DSC, about 1.6:1 | Needs DSC, about 2:1 |
| 1080p 360Hz | Pass, 22.38 Gbps | Needs DSC, about 1.2:1 |
| 8K 60Hz | Needs DSC, about 2:1 | Needs DSC, about 2.5:1 |
| 8K 120Hz | Fail, even with DSC (needs about 4.1:1) | Fail, even with DSC (needs about 5.1:1) |
Results use PC monitor timings (VESA CVT reduced blanking v2 as the headline), not the TV and console timings in CTA-861, so a TV or console may need more bandwidth than shown. RGB/4:4:4 color. DSC verdicts are at maximum compression (8 bpp), the lowest rate VESA's DSC standard allows for 4:4:4, and show the compression each mode needs.
Sources
- HDMI 2.1 FRL article (Allion Labs), retrieved 27 October 2026
- New HDMI 2.1 Technology, part 1 of 2 (Black Box, 2021), retrieved 27 October 2026
- VESA introduces DisplayPort v1.2 (7 Jan 2010), retrieved 27 October 2026
- VESA publishes DisplayPort Standard Version 1.4 (1 Mar 2016), retrieved 27 October 2026
- VESA publishes DisplayPort 2.0 video standard (26 Jun 2019), retrieved 27 October 2026
- VESA rolls out early certification program for HBR3 products (4 Jan 2017), retrieved 27 October 2026
- VESA readies DisplayPort UHBR device certification and begins certification of UHBR cables, retrieved 27 October 2026
- Premium HDMI Cable Certification Program (hdmi.org), retrieved 27 October 2026
- Ultra High Speed and Ultra96 HDMI Cables (hdmi.org), retrieved 27 October 2026
- Thunderbolt 3 vs Thunderbolt 4 (Intel), retrieved 27 October 2026
- Thunderbolt 5 Technology Brief (Intel, Sept 2023), retrieved 27 October 2026
- VESA CVT Standard, Version 2.1, retrieved 27 October 2026
- VESA CVT v2.1 Generator Version 1 (spreadsheet; sheets CVTv2.1 and CVTv1.2a), retrieved 27 October 2026
- VESA Display Stream Compression (DSC) Standard, Version 1.2b (12 Aug 2021), retrieved 27 October 2026
- VESA DSC Source Device Guidelines r1.0, retrieved 27 October 2026
- USB4 (Wikipedia), retrieved 27 October 2026
Data verified 27 October 2026 against these sources. See the methodology for how disagreements are resolved.