HDMI Multiviewer Switch 4x1, PORTTA HDMI Quad Multi-Viewer Seamless Switcher 4 in 1 Out with Loop, Audio Extractor to Stereo, 1080p, 5 Viewing Modes for Security Camera, Gaming Consoles

So you want to play your vintage sega genesis/saturn/snes etc on your OLED TV and you want to sit right in front of the screen like you are 12 years old in your mama's living room while she tells you not to sit so close that you'll ruin your eyes, but you don't actually want the image to be blown up to huge full screen size with giant pixels because nobody makes a reasonably priced small 17"-30" OLED monitor for retro gaming?If so, this box is your new best friend. I use a set of HD Retrovision component cables from the Genesis and Saturn, into an analog component switch/dual-output splitter, then I feed one component output direct to an old-school CRT for latency comparison and I feed the 2nd component output into a RetroTink low latency component to HDMI converter/line doubler, then from that I run the HDMI from the RetroTink into this multiviewer unit and put it into 4 in 1 mode which shrinks the 480p hdmi signal into 1/4th of the 4k frame at 60fps, then from there to an LG OLED TV and when running side by side with the CRT I can discern no added latency, sound and video are 100% in sync between the CRT and the LG OLED TV and the resulting 1/4" size image on my 48" OLED is the best I have ever seen vintage consoles look in my life. Also, in 4:1 mode and with just-scan on in the TV settings one can get the image to be aspect ratio perfect with no stretching and even better geometry than the old CRT, with spherical objects in games appearing as perfect circles on the OLED TV.

I got this to split my screen for sports. Works amazing!

I have a small retro computer setup with a Commodore 64, Commodore 128, and VIC-20. This device allows me to view the output from three separate Raspberry Pi units running virtual floppy drives at the same time on one screen. Easy to setup with a variety of options. My only complaint is a really small one, but it does have a hard time with a 720p output. It tends to flicker a lot as it keeps trying to run 1080. Options on the remote will get it smoothed out eventually and this is anything but a major complaint. I just need to connect it to a 1080 monitor rather than the old 720 TV I am using now!

Very simple to set up. It easily switches between inputs like a Roku, video game, TV, DVD player, or any combination and has a separate volume output where you can watch one thing and listen to another. Nice.Cons; The Blue lights on the front are too bright and it only has a DC input. Dot lights and a USB power input would perfect it.

so nice thing is the picture quality is descent. I don't always go overboard with resolution so it's not a dealbreaker for me. on/off button works so I can shut off all sources from the box. dislikes are first and foremost, it is missing the promised "dual screen mode". Second is when you use multiple screens, you can't adjust the placements. the HDMI jack needs to be plugged into the screen port you want to display it. Also, which isn't a huge deal, you can only have sound from one source at a time, but you can select which source is active. all in all, not bad, but not everything that was promised. Lastly, now this is a personal preference but a remote should run on AA or AAA batteries, not "coin" batteries. Those batteries never last long and are surprisingly expensive for the amount of juice you get. All in all, does what I wanted. just a little disappointing when product is missing promised features.

I love that it has a remote and buttons on the device itself. It is easy to operate and its a small footprint on the table. Having this ability is like being at a bar and watching 4 screens at a time. I hooked up the PS4, a Nintendo Switch, a DTV with an HDMI output, and a Mirror Cast at the same time. This is real spit screen entertainment. You would love this!

I needed the product to display the output of 4 computer screens on one large monitor.Could not even get one display to work.Vendor's trouble shooting invovled turning the device on and off several times.

Works as advertised. The only suggestion is to include a button to switch to mode 2 (2 inputs side by side) instead of having to get up from the couch and do it from the actual unit.