Review on Cable Matters 3-Pack 48Gbps Ultra HD 8K HDMI Cable 6.6 ft / 2m - 8K @120Hz, 4K @240Hz, HDR Support - PS5, Xbox Series X/S, RTX3080 / 3090, RX 6800/6900, Apple TV, and More by Robert Rick

TLDR: Initially 6 out of 6 cables failed diagnosis I have returned all 6 cables to Cable Matters. Cable Matters sent me 3 new cables for free and asked me to test it again. 2 cables still failed (3rd not checked). I contacted Denon support about my AVR-X4700H receiver and got no help because they said they don't support HDMI diagnostics for end users. Cable Matters sent me videos of tests they did in their lab with an identical Denon receiver. and advised me abruptly turning the receiver off and back on before entering the HDMI diagnostics menu. It worked and now the 2 cables I tested previously pass the 40Gbps 8k diagnostics every time. So many thanks to Cable Matters for getting in touch via phone and email as they were very concerned about this review and wanted to investigate further. No thanks to Denon support. Original comment: I bought 2 packs of these "8k, 48Gbps" cables and connected all 6 to my Denon AVR-x4700h receiver's onboard 8k HDMI diagnostics and each of them failed 8k. part of the exam. I sent them all back for a refund. Avoid Avoid Avoid! Save money and buy REAL CERTIFIED 8k cables. oh wait there are currently no officially certified ultra high speed cables on the market. In fact, this means that all modern 8k cables currently on the market are being sold by scammers who circumvent the issue by telling you "we tested them” which means literally nothing and/ Or offer refunds. I bet most people who buy 8k cables now don't have the right test equipment to test their uncertified cables and use them mostly for 4k content and think they can test their video resolution needs in the future , but guess what? These people are being deceived. Update: August 31, 2020 Cable Matters support contacted me to say they have multiple Denon AVR-x4700h receivers in multiple labs, from which they see test results of their own cables via Denon. integrated diagnostics. They also sent me a free pack of new 8k cables and asked me to test it again. I ran another test with at least one of the new cables and again got conflicting but mostly unsatisfactory results. I've looked around the internet and found other owners of the same Denon receiver who have had very conflicting test results for other brands of 8k cables. So either the Denon receiver is having trouble consistently performing these tests, or these uncertified cables really are snake oil. To be honest with this seller and to be as objective as possible, I contacted Denon support to see if there were any known issues with 8k HDMI testing. I have upgraded my rating to 3 stars pending a response from Denon and will provide further updates. s end user support which didn't help because they say HDMI diagnostics is not something they support for end users only for installers and repair partners etc. So I took Cable Matters advice and did a hard power Cycle performed. my Denon receiver before entering the HDMI cable diagnostics menu. It worked in the end and I now keep getting 100% transfer results between multiple cables they sent me for free. I also connected 2 of my old HDMI cables right after that and one of them stopped working at 18Gbps and the other one stopped working at 40Gbps which is weird but hey, i'll take it for now. I have updated my rating to 5 stars,