The answer to the question “does HDMI support 120Hz” is a resounding yes; HDMI cables CAN support 120Hz refresh rate. However, you should note that there are different HDMI interface versions. Newer versions have a higher bandwidth and thus can support a higher refresh rate and resolution.
In other words, whether the HDMI interface would support a 120Hz refresh rate depends upon its version and the resolution you plan on running your monitor at.
For instance, if you have an older HDMI 1.4 interface, it could support FHD at 120Hz without any issues. However, the same cannot be said if you plan to run a 4K resolution on it.
I’ll explain in detail whether HDMI supports a 120Hz refresh rate and, if so, at what resolution and color bit depth.
What are the Different HDMI Versions?
HDMI interface has been evolving because output device demands are increasing. While a decade ago, Full HD resolution and 60 Hz refresh rate were the norms.
Today, display devices can easily offer QHD, 4K, and even 8K resolution at 120Hz or higher refresh rates.
Hence, more than the older HDMI interface version released that was designed for FHD @ 60Hz is needed to cater to the demands of the newer display devices.
The following table explains the popular HDMI versions and their respective specs.
| HDMI Version | Max Resolution | Max Refresh Rate | Max Bandwidth (Gbit/s) | Effective Bandwidth (Gbit/s) | HDR? | Audio Technology Supported |
|---|---|---|---|---|---|---|
| HDMI 1.0 | 1080p | 1080p @ 60 Hz | 4.95 | 3.96 | No | – 8 Audio Channels |
| HDMI 1.1/1.2 | 1440p | 1440p @ 30 Hz | 4.95 | 3.96 | No | – 8 Audio Channels -Super Audio CDs |
| HDMI 1.3/1.4 | 4096 x 2160 (4K) | 120 Hz @ FHD Resolution 30 Hz @ 4k Resolution 24 Hz @ 4k Resolution | 10.2 | 8.16 | No | – 8 Audio Channels – ARC – Dolby TrueHD – DTS-HD |
| HDMI 2.0 | 4096 x 2160 (4K) | 60 Hz @ 4K Resolution | 18 | 14.40 | Yes | – 32 audio channels, – Dynamic Resolution Adaptation (DRA) – High-Efficiency Advanced Audio Coding (HE-AAC) |
| HDMI 2.1 | Upto 10240 x 4320 (10K) | Upto 120Hz @ 10K | 48 | 42.67 | Yes | – 32 audio channels – eARC |
Higher Display Device Specs = Higher Data Rate
One of the critical aspects you need to understand is that the higher the specs of a display device like a monitor or a TV, the more data it will generate. Nominally, the data a display device generates is dictated by three key attributes:
- Resolution
- Refresh Rate
- Color Bit Depth
Higher resolution would generate more data. The same goes for the refresh rate.
Color bit depth defines the number of colors the display can show. Average monitors and TVs have an 8-bit display. Meaning they can show 16.7 million colors. Professional presentations have ten or higher color depths. 10-bit = 1 billion colors.
Calculating Your Data Rate
So to check if your HDMI interface can support your desired refresh rate, resolution, and color depth, you can use a simple equation as follows:
(H + Hblank) × (V + Vblank) × (C x 3) × F
In this equation,
- H is the horizontal pixel count
- V is the vertical pixel count
- C is the color depth
- F is the refresh rate
- Hblank is the Horizontal blanking interval
- Vblank is the Vertical blanking Interval
Blanking intervals are the periods it takes the display device to go from the end of the scan to the beginning of the scan. These are different for different resolutions and refresh rates. For FHD @ 120Hz, they are as follows:
- Hblank = 80 pixels for FHD @ 120 Hz
- Vblank = 60 Pixels for FHD @ 120 Hz
You can also save yourself from the hassle of manual calculation using popular calculators such as this one.
So Does HDMI Support 120Hz?
With the knowledge of the different HDMI version ports and how to calculate your data rate, you can verify whether your interface can support a 120Hz refresh rate.
Let’s give a practical example. Say I have a Full HD monitor with 8-bit color depth and want to operate at 120Hz refresh rate.
Taking the equation above, we get
(H + Hblank) × (V + Vblank) × (C x 3) × F
= (1920 + 80) × (1080 + 60) × (8 x 3) × 120
= 6,566,400,000 bits per second = 6.58 Gbits/s
We know that HDMI 1.4 can support up to 8.16 Gbit/s of effective data rate, and hence at FHD resolution ad with an 8-bit color depth, you should have no issue using the old HDMI 1.4 interface, which is found on even decade-old monitors and PCs.
The following table summarizes your HDMI version to operate 120Hz at different resolutions and color bit depths.
| Refresh Rate | Resolution | Color Bit Depth | Data Rate (Gbit/s) | Required Minimum HDMI Version |
|---|---|---|---|---|
| 120Hz | 1920×1080 (FHD) | 8 | 6.58 | HDMI 1.4 |
| 120Hz | 2560×1080 | 8 | 8.70 | ~HDMI 1.4 |
| 120Hz | 2560×1440 (QHD) | 8 | 11.59 | HDMI 2.0 |
| 120Hz | 3840×2160 (UHD/4K) | 8 | 54.97 | HDMI 2.1 |
| 120Hz | 1920×1080 (FHD) | 10 | 8.24 | ~HDMI 1.4 |
| 120Hz | 2560×1080 | 10 | 10.87 | HDMI 2.0 |
| 120Hz | 2560×1440 (QHD) | 10 | 14.49 | HDM 2.1 |
| 120Hz | 3840×2160 (UHD/4K) | 10 | 32.27 | HDMI 2.1 |
The wrong HDMI Interface Would Present Bottlenecks
While the HDMI interface is backward compatible, meaning you can plug a monitor with an HDMI 2.0 into a PC with an HDMI 1.4 or a TV with an HDMI 2.0 to a home theater system with an HDMI 1.4, using a newer device input device (TV/monitors) with an older output device (PC/console), you would be presenting bottlenecks.
In other words, if a TV is designed to display 4K @ 60 Hz and you connect to a console with an HDMI 1.4, the TV will not work at its full potential.
Also Read: Can I Plug HDMI 2.1 Cable Into a 1.4 Port?
Final Words
So, in the end, the answer to the question “does HDMI support 120Hz” is a yes on the surface. However, to get the in-dean answer, you must check the resolution you wish to run your monitor/TV at and the color bit depth of your display.
In most cases, I recommend you have the HDMI 2.0 interface to run a 120Hz refresh rate. However, the older HDMI 1.4 interface can also suffice, particularly when running at Full HD resolution.
FREQUENTLY ASKED QUESTIONS
1. Does HDMI 1.4 Support 120Hz?
HDMI 1.4 can only definitively support 120Hz at FHD with an 8-bit monitor.
It may be able to support 120Hz also at 2560×1080 (ultrawide screen HD) with an 8-bit monitor, but there may be some lags and stutters, most of which would be noticed.
2. Does HDMI 2.0 Support 120Hz?
Yes, it does. HDMI 2.0 can support a 120 Hz refresh rate for 8-bit and 10-bit widescreen Full HD display,i.e., 1080P, and for the 8-bit ultrawide screen, QHD displays, i.e., 1440p.
3. Does HDMI 2.0 Support 120Hz 1080P?
Yes, quite easily. HDMI 2.0 can support well beyond 120Hz @ 1080p resolution
4. Does HDMI 2.0 Support 120Hz 1440P?
Yes, it quite easily can. If you have an average TV or a monitor with an 8-bit color depth, 120Hz at 1440P would not be an issue.
If you have a professional grade 10-bit monitor, then you are pushing the limit, but still, HDMI 2.0 should be able to support it quite well.
5. Do You Need HDMI 2.1 for 120Hz Gaming?
No, it would be best to have an HDMI 2.1 interface for 120Hz gaming UNLESS you wish to game on 4K monitors.
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