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, Black

Works at 4k@120hz and 4k@144hz vrr, hdr all good. Didn't work until I updated the firmware on their support website. I wanted to connect a TCL 75 Q7 TV in my other room using this adapter. My Gigabyte 4080 only has one hdmi 2.1 port and that was already connected to my 42 C3 I am using as a monitor. So this adapter worked fine. Now we shall see just how long it will last.

Works well enough for a PC for dedicated surround sound. A bit short but does the job

This dongle works for my Windows laptop but it does not work for my Mac. I have a CalDigit TS4 which only has a DP 1.4 display output and my monitor only has one which is already taken up by another PC. The monitor has two HDMI ports so I thought this would be perfect. Unfortunately, it does not display my Mac when connected. It works fine with the work laptop which is a Windows machine. I went through the drivers and made sure everything was up-to-date. I think I might try a different MFG at some point.Update:I tried this again and after updating my Mac I get a solid 2 seconds of display and then it immediately shows vertical lines on my external monitor. I've eliminated every other device/cable having issues so it must be this adapter.

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.

After having some issues with HDMI and my LG OLED C1, I read that using the displayport is a better way to go. Since TV's don't have displayports I grabbed a DP to HDMI adapter I already had and gave it a try. After a few weeks with no issues I decided to find a better adapter that did 4k@120hz. I received it today(3/2/2023) but so far it seems to be working great.With my LG OLED C1 I can get 4096x2160@120hz 10bit HDR10.Update 1/1/24: I'm now using this with a 4090 and an optical HDMI 2.1 cable. Even though the 4090 has an HDMI 2.1 port I run in to issues where I'm forced to unplug the cable before the monitor is recognized. So far the working solution is to use the cable matters DP adapter + HDMI power injector + HDMI 2.1 optical cable. Since adding this frankentstein solution to my setup my monitor now recognizes the pc on every boot. I'm planning to replicate this setup for my second monitor since the optical DP cable is having the same issue. It's not ideal but I get the correct picture with HDR, sound, and the all the correct resolutions I should be getting by using this janky setup, if it works it's not stupid.1/1/25 update: I'm now using this with a different PC connected by 100ft optical cables in a different room. Earlier this year I upgraded to a 4090, and moved my PC to a different room due to heat and noise, with 100ft optical cables. At first I was having issues with my HDMI 2.1 optical cable but after pulling this converter out of the closet and using the Displayport instead of the HDMI port my issues went away. If you are using this adapter with an optical cable I highly recommend you also use a HDMI power injector. I'm getting full 4k@120 with HDR and I have absolutely no complaints about this adapter.One thing I did notice when I tested using 2001: A Space Odyssey 4k remaster was that Plex is telling me I have 5.1 surround Bitrate-2197 kbps. While the TV only seemed to recognize 2 audio channels in the HDMI diagnostics hidden menu. I also confirmed this with Aliens (1986),5.1 24 bit DTS@1509kbps, installed on my pc and using VLC to playback. This could be windows shenanigans since I haven't paid for dolby, but without a proper surround setup I cannot confirm.**Edit: Turns out the surround issue is due to windows NOT the adapter. You can think Microsoft for its extremely poor implementation of audio, although without testing I can't say that Linux does it any better. Also while playing around I did notice some audio skipping, I couldn't figure out what was causing the issue since it was intermittent. Then I remembered another review that mentioned the adapter getting hot, so I slapped a few raspberry pi heatsinks I had on the adapter. The skipping issue went away almost immediately. I also checked the firmware and found it to be up to date, the utility Cable Matters has on their website made checking/updating the firmware very easy. I still give this adapter 5 stars since it does everything its advertised to do, although it could do a better job of cooling.Edit 03/20/2023: I'm now using this with the cable matters Active 8k HDMI Fiber Optic Cable 300047-BLK-15M. The adapter and cable are still getting 4k@120hz VRR 10bit HDR, but now with a 15m/49ft cable. (added 2 pictures to review showing LG hidden menu & windows 10 settings)