DisplayPort 2.1 became a much bigger talking point than expected when AMD revealed its upcoming RX 7900 XTX and RX 7900 XT GPUs. It is the latest standard of DisplayPort, a version of the 2.0 specification released in 2019, and it is a natural inclusion for next-generation GPUs. There’s just one problem – Nvidia’s behemoth RTX 4090 still uses DisplayPort 1.4a.
Although the 1.4a specification is still more than enough for most people, the inclusion of DisplayPort 2.1 gives AMD an advantage for this generation. No, I’m not here to sell you on 8K gaming—in some parts of the world, 8K might not even be possible—but for a crowd of competitive gamers and VR enthusiasts, DisplayPort 2.1 could mark a big shift.
An update four years in the making
VESA, the company that defines and certifies the DisplayPort standard, released DisplayPort 2.1 in October 2022. It usually takes years for products to come to market to support a new standard, but DisplayPort 2.1 is not that new. It’s a refresh on DisplayPort 2.0, which launched in 2019, and a massive improvement over DisplayPort 1.4 that we’ve seen since 2016.
Like any new connection, it’s all about bandwidth. DisplayPort 1.4a, which you’ll find on all recent graphics cards short of the Intel Arc A770 and A750, as well as AMD’s upcoming RX 7900 XTX, is at 25.92 Gbps maximum data rate. DisplayPort 2.1 goes to 77.37Gbps (theoretical bandwidth is higher, in case you see different numbers, but this is the actual data rate possible over the cable). If you run some, admittedly complicated, math, you’ll find that the required data rate for 4K at 120Hz with HDR enabled is 32.27Gbps – higher than what DisplayPort 1.4a is capable of.
Monitors like the Samsung Odyssey Neo G8 support 4K at 240Hz with only DisplayPort 1.4a, so what gives? DisplayPort (and HDMI now) uses Display Stream Compression (DSC) to reduce the amount of data. DSC is not mathematically lossless, but it is visually lossless. And it can reduce the required data up to a 3:1 ratio, reducing the 32.27Gbps number down to 10.76Gbps. That’s great, and DSC is the only reason that DisplayPort 1.4a hasn’t already been shot to gross.
The problem is that the limitations of DisplayPort 1.4a start to appear, even with DSC enabled. A theoretical 4K monitor at 360Hz wouldn’t be able to run at its full refresh rate, even with DSC compression of 3:1 (the required data rate is 36.54Gbps, in case you were wondering). And higher color depths for HDR add even more bandwidth requirements, as do higher refresh rates and resolutions.
A 4K 360Hz monitor might sound crazy now, but we have hardware capable of driving such a display. AMD claims 295 fps at 4K in Apex Legends and 355 fps and Overwatch 2. In addition, the RTX 4090 can push over 300 fps at 4K Rainbow Six Siege, and the frame generation capabilities of DLSS 3 and the upcoming FSR 3 are sure to challenge the position of 4K at 240Hz maximum that we currently have on gaming monitors.
Most people don’t need that extra refresh rate, but let’s be honest; most people don’t need to spend $1,600 (or even $1,000) on a GPU either.
We have the hardware
Oddly, we don’t wait for hardware to take advantage of monitors. We are waiting for monitors to show new hardware. Samsung has already tested its “8K” Odyssey Neo G9 for CES this year – for the record, it’s not true 8K, but rather two 4K displays side by side in a 32:9 aspect ratio – and we expect to see at least a handful 8K gaming monitors to be shown at the show alongside the Samsung display.
This display is also a good touchstone. Assuming Samsung wants to stick with a 240Hz refresh rate like the current version has, you’ll see a data rate of over 45Gbps with HDR on (36.19Gbps with HDR off), and that’s with 3:1 compression. This is all theoretical at the moment, we’ll have to wait until we see this display and other 8K options, but the numbers suggest that the RTX 4090 won’t be able to because of its DisplayPort 1.4a connection (at least at full refresh) rate, DisplayPort is backwards compatible).
There’s no need to limit this conversation to 8K or super high refresh rates at 4K, either. OLED TVs masquerading as gaming monitors are becoming more and more popular, and they could see huge benefits from 5K and 6K resolutions. As I saw with the LG UltraGear 48 OLED, the pixel density needs to be higher for such a large screen so close to your face. DisplayPort 1.4a can drive 5K and 6K with DSC, but not at refresh rates above 120Hz and not at higher HDR color depths.
That coverage of the data rate also shows up in VR. The Pimax Crystal, which is currently a Kickstarter campaign, should require about 29Gbps of data with DSC at 3:1 based on the specifications. That’s within what DisplayPort 1.4a is capable of, but it’s reaching the limit.
From large form factor displays to VR headsets to higher refresh rates at 4K, DisplayPort 1.4a is starting to reach its full potential. If both AMD and Nvidia stick with DisplayPort 1.4a, that wouldn’t be a big deal. Display manufacturers would adapt to the capabilities of what is currently on the market. But AMD is opening the floodgates with their new GPUs.
An important difference, but not a selling point
Out of all the things to base a buying decision on, the DisplayPort standard should be very far down on this list. We still have to see how AMD’s new GPUs work, what features such as FidelityFX Super Resolution (FSR) 3.0 bring, and if you push past the barrier gaming monitors, it also makes sense.
But that’s where the trend is going, and the difference between DisplayPort 1.4a and 2.1 could become more relevant much sooner than we predicted – at least for a high-end class of gamers who want to experiment with bleeding-edge technology .