Only if the source, selected output, receiver/soundbar path, TV input and TV mode all support 4K at 120 Hz. Use a certified Ultra High Speed cable, but a cable cannot add bandwidth or features to an unsupported port. First, check the exact supported resolutions on both endpoint ports and bypass receivers/switches.
What this covers
- A game console or PC connected to a 4K 120-Hz-capable display
What it does not cover
Try in this order
0 of 9 completedEstablish the exact starting state
ReversibleCheck the exact supported resolutions on both endpoint ports and bypass receivers/switches.
Separate the fault or decision boundary
ReversibleTest direct at 4K60, then 4K120, then HDR/VRR one feature at a time.
Apply the narrowest correction
ReversibleUse the correct enhanced-bandwidth input and mode, certified cable and supported source output.
Check what both ends support
ReversibleLook up the exact resolutions and refresh rates that the source's output port and the TV's input support, and note any receivers or switches in the path. A cable cannot add a feature that an end does not have.
Test 4K60, then 4K120, then HDR and VRR one at a time
ReversibleConnect directly at 4K60 first, then raise it to 4K120, and then add HDR and variable refresh rate one by one. This shows which feature the path fails to carry.
Use the right input and mode with a certified cable
ReversibleChoose the TV's input that supports the high-bandwidth mode and turn on its enhanced setting, use a certified Ultra High Speed cable, and confirm the source's output. Then read the source's status screen or the TV's signal information during a 120 Hz game.
Scan the label before you blame the cable or the TV
ReversibleScan the QR code on the packaging, or look for the Ultra High Speed name on the jacket. A cable without the label is an uncertified cable whatever its packaging claims.
Then check the port, not just the cable
ReversibleThe cable is only one link: the TV port and the source must both support the mode. Use the port your TV's manual names for full-bandwidth input and test the source's output setting.
Verify before escalating
ReversibleRead the source's output/status screen and TV signal information during a 120-Hz title.
The cable standard
What the certified cable is and how to verify one
Whether a cable is the limit is decided by its certification, not its length or its price.
- Ultra High Speed
- The HDMI Licensing Administrator's Ultra High Speed cable is for system configurations supporting up to 48 Gbps maximum bandwidth. The newer Ultra96 cable is for 96 Gbps and 8K at 60 Hz with 4:4:4 formats.
- The certification label
- A certified cable carries an Ultra96 or Ultra High Speed certification label on its packaging with a QR code that standard QR apps can scan to confirm certification, and the cable name is also required to appear on the outer jacket.
- Retail verification
- Manufacturers may show a verification banner on retail websites that can be clicked or scanned to display the brand, model number and length.
- Ongoing audits
- The HDMI Forum buys cables from retail channels and tests them, and cables that pass receive a letter confirming they passed the compliance audit.
Stop boundary
When this stops being a self-service repair
- !Change one part of the path at a time, and do not buy several cables at once before you have confirmed the source and the TV port support the mode.
Evidence ledger
Sources behind this answer
Exact questions
Common questions about “Will an HDMI 2.1 cable fix 4K 120 Hz?”
Will a new HDMI cable give me 4K at 120 Hz?+
Only if the source, the TV port, any receiver and the settings all support it. A cable cannot add bandwidth to an unsupported port.
What is an Ultra High Speed HDMI cable?+
A cable certified for the full bandwidth of HDMI 2.1, which is needed for 4K at 120 Hz with HDR.
Why does only one HDMI port on my TV support 4K120?+
Many TVs enable the full bandwidth on only some ports, and the port may need an enhanced-format setting turned on.
Does the cable length matter?+
Yes. Long passive cables can fail at the highest bandwidth, so use a short certified cable or an active one.
How do I tell a certified cable from an uncertified one?+
The HDMI Licensing Administrator says certified cables have a certification label with a QR code you can scan and the name printed on the jacket.
What is the difference between Ultra High Speed and Ultra96?+
Ultra High Speed is for up to 48 Gbps; Ultra96 is the newer 96 Gbps cable, described as supporting 8K at 60 Hz with 4:4:4 formats.
What else must match?+
Both devices and the port need to support HDMI 2.1 features.
Is a certified cable needed?+
A certified Ultra High Speed cable is recommended.