DisplayPort vs HDMI for 1440p 300Hz: Which Cable and Port Do You Need?

For 1440p at 300Hz, you need DisplayPort 1.4 with Display Stream Compression (DSC) or DisplayPort 2.0/2.1; HDMI 2.1 can also do it, but only if your monitor and GPU both support HDMI 2.1 with DSC. The cable and port must match on both the graphics card and the monitor, and a lower version on either side will cap your refresh rate.

Why 1440p 300Hz Is Demanding

At 1440p (2560×1440), a 300Hz refresh rate means the display draws 300 frames every second. That requires a massive amount of data. The raw bandwidth needed is:

Resolution: 2560 × 1440 = 3,686,400 pixels
Color depth: 8-bit per channel (24-bit total) = 3 bytes per pixel
Frame size: 3,686,400 × 3 = 11,059,200 bytes ≈ 10.55 MB
Per second: 10.55 MB × 300 = 3,165 MB/s ≈ 25.3 Gbps

That is the raw data rate before any overhead. Real-world signaling needs even more. Without compression, you need roughly 32 Gbps of usable bandwidth. HDMI 2.0 (18 Gbps) and DisplayPort 1.2 (17.28 Gbps) are far too slow. Only the newest standards can handle it.

Bandwidth Comparison: DP 1.4, DP 2.0, HDMI 2.1

Here is the practical bandwidth of the relevant standards:

DisplayPort 1.4: 25.92 Gbps raw, about 25.92 Gbps data. With DSC, it can drive 1440p 300Hz comfortably. Without DSC, it is borderline—some monitors use chroma subsampling to fit, but that reduces color quality.
DisplayPort 2.0/2.1: 77.37 Gbps (UHBR20) or 54 Gbps (UHBR13.5). Plenty of headroom for 1440p 300Hz even without DSC, and supports higher color depths.
HDMI 2.1: 48 Gbps raw, about 42.6 Gbps data. With DSC, it easily handles 1440p 300Hz. Without DSC, it is also enough (42.6 Gbps > 32 Gbps), so it can do 1440p 300Hz at 8-bit color.

Note: HDMI 2.0 and DisplayPort 1.2 are not enough. DisplayPort 1.3 (32.4 Gbps) is also insufficient without DSC.

What About DSC (Display Stream Compression)?

DSC is a visually lossless compression algorithm. It reduces the data rate by about 3:1, so a 25.92 Gbps DP 1.4 link can carry a 77 Gbps stream. For 1440p 300Hz, DSC is almost always used on DP 1.4 and HDMI 2.1 systems. It is not the same as chroma subsampling (which drops color resolution); DSC preserves full color fidelity. In practice, you will not notice a difference.

Most 1440p 300Hz monitors require DSC to hit the full refresh rate. If your GPU or cable does not support DSC, you may be limited to 240Hz or lower, or you may have to reduce color depth to 6-bit.

Which Ports and Cables Actually Work?

You need the port on both the GPU and the monitor to support the same standard. A cable rated for a lower version will bottleneck the link.

DisplayPort 1.4 cable: Certified for HBR3 (8.1 Gbps per lane). Works for 1440p 300Hz with DSC. Look for “DP40� or “DP80� certification on the cable.
DisplayPort 2.0/2.1 cable: Needed for DP 2.0/2.1 ports. Use a certified cable (DP80 for UHBR20).
HDMI 2.1 cable: Certified “Ultra High Speed� cable (48 Gbps). Works for 1440p 300Hz with DSC.

Older cables (DP 1.2, HDMI 2.0) will not work. Even if the cable physically fits, it will not carry the signal.

How to Choose: DP vs HDMI for Your Setup

Check your GPU’s ports first. Most modern GPUs (NVIDIA RTX 30/40 series, AMD RX 6000/7000 series) have DP 1.4a and HDMI 2.1. Then check the monitor’s specs. The monitor’s manual will list which ports support 300Hz.

Identify the ports on your graphics card and monitor.
If both have DP 1.4 or higher, use a DP cable. DP is generally preferred for high refresh rates because it has been the standard for PC gaming longer.
If only HDMI 2.1 is available, use a certified HDMI 2.1 cable.
If you have a DP 2.0 port, use a DP 2.0 cable for future-proofing.

In practice, either works. The key is that both ends support the same version. A DP 1.4 cable with a DP 1.2 port will not do 300Hz.

Common Problems and Misconceptions

“I have a 300Hz monitor but it only shows 240Hz.� This is almost always a bandwidth issue. Check that you are using a cable that supports the full bandwidth, and that the monitor’s OSD is set to the right input mode. Some monitors have a “DSC� toggle that must be enabled.

“HDMI 2.1 is better than DP 1.4.� For 1440p 300Hz, both work. HDMI 2.1 has more raw bandwidth, but DP 1.4 with DSC is equally good in practice. The difference matters only for 4K 240Hz or 8K, where DP 2.0/2.1 or HDMI 2.1 without DSC might be needed.

“I need a special cable for 300Hz.� Not special, but certified. A cheap uncertified cable may not meet the spec and could cause flickering or no signal.

“Can I use an adapter?� Active adapters (DP to HDMI) exist, but they often limit bandwidth. For 300Hz, avoid adapters unless you know they support the full bandwidth. A direct cable is always safer.

Cost and Availability

Certified cables are not expensive. A DP 1.4 or HDMI 2.1 cable typically costs $10–$20 for a 3-meter length. DP 2.0 cables are newer and may cost a bit more. Avoid extremely cheap cables that do not have certification logos.

Frequently Asked Questions

Can I use a DisplayPort 1.2 cable for 1440p 300Hz?

No. DP 1.2 has a maximum data rate of 17.28 Gbps, which is not enough for 1440p at 300Hz even with DSC (DSC is not supported on DP 1.2). You need at least DP 1.4.

Does HDMI 2.0 support 1440p 300Hz?

No. HDMI 2.0 has 18 Gbps bandwidth, which is insufficient. You need HDMI 2.1 with DSC (or without, if the monitor supports it).

Is 1440p 300Hz better than 4K 144Hz?

For competitive gaming, 300Hz gives a smoother experience with less motion blur. For visual fidelity, 4K has more pixels. It depends on your preference and GPU power. At 1440p 300Hz, you need a very powerful GPU to hit high frame rates in modern games.

Do I need a special GPU to output 1440p 300Hz?

Your GPU must have a port that supports the required bandwidth. Most GPUs from the last few years (NVIDIA RTX 20/30/40, AMD RX 5000/6000/7000) have DP 1.4 or HDMI 2.1. Older GPUs with DP 1.2 or HDMI 2.0 will not work.

Will a longer cable reduce my refresh rate?

Longer cables can have signal degradation, but a certified cable up to 3 meters (10 feet) should work fine. Beyond that, you may need an active cable or a signal booster. The standard does not change, but the signal quality can.

What if my monitor has only HDMI 2.1 and my GPU has only DP 1.4?

You would need an active DP 1.4 to HDMI 2.1 adapter that supports DSC. Such adapters exist but are not common. It is better to use a direct connection: if the monitor has DP, use that; if not, check if your GPU has HDMI 2.1.

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.

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