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 have a 50 foot active fiber HDMI cable from my PC to the living room TV. The PC had an issue where it would start sending invalid signals to my main displays when the TV was turned off.I used this adapter to connect the PC end to a DisplayPort connector on my GPU, and as a side effect my setup now works perfectly: 4k HDR and audio to the TV with no lag or drops, and no more display issues connected to power state.

I received this item anticipate it will work to convert my 5070 Ti from DP to HDMI 2.1 to connect to another TV, but the initial config doesn't work. it can merely output 4k@120 YUV 422 and screen color shift when reboot with HDR.I downloaded the adapter VRR firmware in cable matters website in order to flash, but it gives me firmware checksum mismatch error all the time. I had to find a old AMD GPU to do the flash, then everything goes perfect:RGB 10bit HDR VRR/Freesync support.I hope they can investigate the firmware update error on RTX 50 cards.

This is a very simple review: this adapter is exceptionally glitchy, unstable, and simply doesn't work as advertised.Use case: MSI GTX 1060 6GB Gaming X that I simply wanted to get a 4k@120Hz signal out of.The DP version for this card is 1.4; the required version for this adapter.I used both a certified 8K/4K@120Hz HDMI 2.1 cable and the cable from the Xbox Series X (also 8k/4K@120Hz certified.)Finally, I have a 77" LG C3 with a 4K@120Hz-enabled HDMI 2.1 ports.Expectation: the computer turns on and displays the option to set it to 120Hz mode.Reality: it turns on and Windows 11 Pro gives you the option to set to 120Hz, at which point the TV freaks out and displays horrible "snow" like it's CRT trying to tune into an non-existent VHF signal.Fine, turn it off and back to 60Hz. It works fine at 60Hz. (So does HDMI 1.4...), let's try to restart the computer.Oh, now the computer hangs and has absolutely no display output on HDMI or DP on this or a Viewsonic (blah blah blah irrelevant 27" 1440P monitor.)Cool.Remove the adapter and restart, now it displays on both, unplug the monitor, set back to 120Hz, and still distortion.Google: "Firmware update to enable DP 1.2 and 1.4 features on Pascal-generation cards (10xx): "Some... 1030 [Doesn't support DP, LOL Nvidia], 1050, 1060, 1070, and 1080 and all variants, i.e. 1080ti cards might not support 1.2 and 1.4 features until this firmware update is applied."Okay, let's install that. Computer restarted and hung again, restart again with no adapter plugged in, comes up fine.Annnd it still goes snow mode when you set it to 120Hz mode.Re-running the firmware update tells me it's on the correct version.Other suggested resolutions from other reviewers: turn off G-sync in Nvida Control Panel, enable HDMI Deep Color on the TV, try Game Mode, latest drivers, etc.It simply doesn't perform the advertised task of converting a DP 1.4 port into a HDMI 2.1 port, despite all other pieces supporting the signal. My Series X runs at 4K120 all day long. My TV reports all of the checkboxes work with the system. (The LG C3 has 3 identical inputs with the remaining one simply supporting eARC, they all support the same inputs. For grins, I did try all 4.)Nvidia control panel didn't let me see or set set anything above 60Hz. I made a custom resolution and the TV freaked out when I applied it. I did try changing RGB/YCb Cr4:2:0, and 4:2:2 but it didn't like any of them.Also, as reported by others, even at 4K 60, the audio drops out randomly with 5.1, Dolby, and DTS content. This seems to be a bug as well.)Cable Matters states on their website:For dedicated graphics, an Nvidia RTX 2060/3060 or an AMD Radeon RX 6000 Series or newer graphics are required to achieve 8K@60Hz video.4K@120Hz and 8K support may require a firmware update on some 8K TVs.4K@120Hz and 8K support must be manually enabled on some 8K TVs.VRR/G-Sync/FreeSync are not supported.(The first statement is false, as you can easily get 8K60 working on 10000-series cards over DP 1.4 when it's true DP -> DP.)Now, Cable Matters' website has a firmware update option for the 102101, but mine is already on the latest 7.02.120 version available.The specs, asterisks, and warnings all pertain to: requiring DP 1.4 and requiring a 2000 or 3000 series card for this to work at 8K. They all say you might need to update the software on your card, TV, and adapter. That's all done. It doesn't workAn adapter shouldn't hang a computer when it starts up... ever.I'm officially out of ideas and patience. It's going back to Amazon.

This is the ONLY converter I have tried that can power 2k@240hz monitor without issues from source DP (RTX5070TI) to the HDMI I have connected. Love it, despite the lower rating, this one is legitimate and I highly recommend.Other ones that convert DP to HDMI all have issues pushing it to 2k@240hz, this is the only one that works. Get this one, you won't regret it!