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

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)

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 fine i get my full 240Hz with rtx 5080. But no display out of rx 9070xt. I belive it has somthing todo with the 9070xt and not the adapter its self, can only get 85hz with two hdmi connected to 9070 xt

I bought this because a lot of reviews said that it supported variable refresh rate. On Linux, AMD GPUs cannot output proper HDMI 2.1 due to HDMI being an awful standard, but I wondered if using a Displayport to HDMI adapter could get around this limitation.When I first took the adapter out of the box, I didn't have a proper HDMI 2.1 cable to test it with, but it did seem to work at 4K YCbCr 120Hz with VRR under Linux on my Dell 4K 144Hz monitor and confirmed that the refresh rate was indeed varying looking at my monitor's OSD. I then tried it with my old Samsung 2018 TV that has the old AMD-specific FreeSync and it did not work correctly in Linux (TV would flicker on and off whenever the frame rate dropped) but this was also true using the HDMI port directly on my GPU, so no fault of the adapter it would seem. I then tried the same on Windows and it worked great. The TV would run with AMD FreeSync with this adapter and with it directly connected to my GPU's HDMI port. Chalking this one up to Linux driver support.I then got a proper HDMI 2.1 cable and hooked it up under Linux. I was able to enable 4K 144Hz VRR mode but it seemed to be in YCbCr mode, but it would flicker on and off. I tried again with Windows and it seemed to work sometimes, but then the monitor would flicker on and off some other times.I then decided to try the firmware update everyone was talking about, but worried that it would just remove VRR capability entirely. Sadly, that's exactly what it did. It seems to be stripping the VRR support from the EDID so neither Linux nor Windows recognizes that the display supports VRR at all. This is unacceptable, taking away functionality that was previously offered with a firmware update is not an acceptable "fix" for flaky VRR support. At very least put it in the firmware release notes that you're intentionally breaking this functionality entirely rather than fixing it. I wish there was a way to downgrade the firmware back to a VRR-supporting one, because a display without VRR is useless for gaming. I tried to ask a question on their site but was unable to create an account, with a "try again later" error. So I can't even ask a question about getting this fixed because their tech support site won't let me register.Also, on Linux it seems to boot up with only 60Hz supported. If I unplug and plug it back in to the GPU, then it supports 144Hz. On the old firmware it would go into YCbCr color mode but on the new firmware it seems to stay in RGB color mode, but without the option to enable VRR now.On Windows with the old firmware, it wouldn't even display a picture when booting up with my Dell monitor attached, regardless of HDMI cable used. I had to plug the monitor directly into the HDMI port of the GPU and then back to the adapter and finally it showed a picture. On Windows it didn't go to YCbCr, it stayed at RGB and let me enable VRR but then started flickering on and off after successfully running the NVIDIA GSYNC pendulum demo (which demonstrates VRR on any GPU, not just NVIDIA). That's when I updated the firmware and now no more VRR at all.If they can't re-add VRR support I will be returning this adapter.

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