Cable Matters 8K DisplayPort 1.4 to HDMI 2.1 Adapter with 4K 240Hz / 8K 60Hz, Unidirectional DisplayPort to HDMI 2.1 Cable Adapter, Supports RTX4080, RX7900, Not Work with PS5/Xbox, No VRR Support

I bought three of these Cable Matters DisplayPort 1.4 to HDMI 2.1 adapters to drive my LG OLED TVs as monitors from an RTX 5080, and they’ve been absolutely flawless. The biggest win? They fully support VRR—and all three arrived preloaded with the 7.02.120_forVRR firmware. I had downloaded the firmware ahead of time expecting to flash them manually, but Windows immediately showed a VRR notification for each one. I verified with the Cable Matters firmware utility that all three adapters already had the correct version installed. The tool is simple and well-designed, so even if I’d needed to update them, it would’ve been easy.I’m running them at 2160p120 HDR RGB 10-bit, and they also handle YCC 4:4:4 perfectly. Since DisplayPort 1.4 is bandwidth-limited, it’s great to see the adapter properly passing through DSC (Display Stream Compression) from the 5080 to the 42" LG C2 without any glitches or image degradation. I’ve paired each adapter with Zeskit 48Gbps HDMI cables, which I highly recommend—this ensures stable bandwidth for 4K120 HDR with RGB 10-bit and VRR without signal drops or handshake issues.Over the past few days of testing, they've been rock solid—no flickering, no handshake delays, and no stability issues through reboots, resolution changes, or long sessions. HDR signal passthrough works flawlessly, with accurate color, proper contrast levels, and clean gradients—no banding or chroma issues observed. These adapters also run cool and feel well-built, with a compact and flexible design that makes them easy to route even in tighter setups without crowding nearby ports.Now that I know these work reliably, I’m planning to expand to a triple OLED setup using three 42" LG C4 TVs as monitors. These adapters are perfect for unlocking full-feature HDMI outputs on NVIDIA cards that typically only offer a single HDMI port—now I can run four displays at full 4K120 HDR with RGB 10-bit and VRR.Can’t recommend these enough.

I'm getting 4K VRR 144hz on an Asus 4090 to Hisense U7K. The cable you use matters. Had to try a few of my 8K Hdmi cables until I got it working. Nvidia control panel will let you apply G SYNC too. Currently running 55" triple screen 4K 144hz VRR with HDR and 8bit Full RGB. No flicker.I do have one issue and that is when starting the PC from shut down, the screen with the adapter will turn of with a RED TINT. I fix it by going into the TV INPUT SETTINGS and reaffirm I want Enhanced 144/240hz and it will resume working as intended. However if I start the PC from sleep I have no problem with a red screen. Works perfectly fine.For some reason I don't know if it's the TV or adapter but I can NOT get 4k 120hz VRR. I tried all input settings on the TV, Windows 11, and Nvidia Control panel. It just didn't want to do 4k 120hz VRR. It will do 4k 120hz however without the VRR. It's strange because it will give me 144hz VRR but not 120hz? Welp as long as it works is all that matters. Hope this helps.

I picked up this Cable Matters 8K DisplayPort 1.4 to HDMI 2.1 adapter to connect my DisplayPort-equipped GPU to my HDMI 2.1 TV, and for the most part, it works as advertised. Build quality is excellent — the braided cable feels durable, the molded strain relief should help it last, and the LED connection indicator is a nice touch. It supports high resolutions and refresh rates, HDR, and surround sound, making it a great option for gaming or 4K/8K media.However, there’s one important technical caveat that isn’t clearly explained in the product specs. While the adapter claims HDMI 2.1 support (8K@60Hz, 4K@120/240Hz), it’s still limited by the DisplayPort 1.4 bandwidth on the source side. That means those higher refresh rates and resolutions often rely on heavy DSC (Display Stream Compression), which can noticeably reduce visual quality, especially in fast-moving content. If you expect full uncompressed HDMI 2.1 performance, this limitation may be disappointing.For reference, my monitor is a Asus 42" 120Hz 4K OLED with HDR and full 10-bit color. On a display of this caliber, DSC would be a gross degradation of quality, introducing artifacts and compression that completely defeat the purpose of such premium image fidelity. Because of that, I will never enable DSC and expect uncompressed signal quality whenever possible.For most users connecting a modern GPU to a high-refresh-rate monitor or TV, it’s still a solid and reliable adapter — just go in knowing that the bottleneck is DisplayPort 1.4, not HDMI 2.1.