Iogear4K UHD DisplayPort KVMP 2-Port with Wireless Keyboard -Mouse GCS1902-KM

I think this is my 5th IOGear KVM of the pricey variety in the past 15 years. They've all performed well. Only one had a power supply give out. Since getting a Dell U3219Q I wanted one of these because my existing one could not handle 4k and at the time they didn't have one that supported 60hz. Then this was born and I hesitated for over a year because of the price. So I used the HDMI and DP ports on the monitor and switched screens using the monitor software. Then used an even older IOGear KVM to manage the KB/mouse.Adding a laptop allowed me to finally justify the costs. BUT - turns out there's ONE catch in my particular scenario. Obviously this switch is all DP but my laptop only has HDMI. Simple enough I though, I have a 4k HDMI -> DP cable I'd gotten at BB on a whim one day. This just did not work at all. Could not get the laptop to display anything on the U3219Q.So the KVM is connected to the DP on the monitor. I just ran an HDMI cable from the laptop to the monitor and a USB cable from the laptop to the KVM. The monitor is smart enough to hunt for a signal when one goes missing. So when I switch between the desktops connected via DP and the laptop, it works just fine. Switching away from a desktop kills the DP connection between it and the monitor - so the monitor hunts around, sees the HDMI signal, and displays the laptops screen.That cable that didn't work is rated 4k so I'm not really sure why HDMI -> DP didn't work. Maybe it's something to do with the laptop, I have no idea. My workaround works just fine so I'm not motivated to figure out where the problem lies. I did use a similar adapter (short, not a full cable) recently to connect my prior HDMI KVM to a newer desktop that only had DP. That worked. Maybe I'll get another one of those and try it. If that works I'll post an update.I've used the Scroll-lock + number method for years to switch between devices. I can't remember if that's something I had to enable in the past or not. Really liked that this one supported that out of the box. Just put the manual away after that.<update> I just learned something. Though no fault of IOGEAR, apparently some graphics cards don't behave well in a Windows environment when using a DP connection. It's nothing terrible, just terribly inconvenient if you always have allot of applications running that are not minimized and you're switching back and forth. For me, it's random - but sometimes when I switch, all of the windows that were open get resized (shrunk) on the machine I'm switching TOO. According to searches, this is widely known but new to me. If your running Windows and your monitor and machines all have HDMI connections, get the GCS1934H. SAME switch, just HDMI instead of DP. I'd never heard of this quirk with DP connections. IOGEAR support was lightning fast to reply and lay out all the details.

This KVM switch comes with two USB 3 Hub ports. 1 in front and 1 in back. I've connected the back USB 3 port using a hub extension cable to a ViewSonic XG monitor. I have my camera, headset, and programmable keyboard connected using the XG monitor as an extension to the KVM USB hub.Programmable keyboards with dual interface cables will not work with this KVM but it appears so far that programmable mice will which is why I used the monitor to interface the keyboard.Front USB hub works well with removable drivesFor those having HDMI only video cards, you will need a USB powered HDMI to Game Port adapter on the PC side which are easy to find.

Pros:- works with both Mac and PC- much smaller than I expected as I previously used the GCS1644 with dual DVI- includes 4 sets of DP and USB3 cables- power adapter is a brick vs a wall wart- works with Caldigit TS3 Plus TB3 dock for mac computers- made with metal chassis- displays nicely on a UHD tvCons:- doesn't work with adapters (HDMI, DVI, Thunderbolt 2 to DP)- up to 5 second delay when switchingI bought the GCS1904 4-Port DisplayPort KVM to connect these computers:- Lenovo M83 Tiny- 2016 MacBook Pro- Zotac BI320- 2014 Mac MiniIt works well with my M83 and MBP but not the BI320 and MacMini. I use a TS3 Plus dock with my MBP. I don't use the BI320 and macmini as much any more so although it's not working for all my computers, it works for the 2 main computers that I use probably 99% of the time. I can still use this KVM to switch the keyboard and mouse for my BI320 and macmini for now until I am able to find a display solution for them (possibly an adapter with an active monitor converter). The BI320 can only do 1920 x 1080 but that shouldn't matter.I originally bought a much cheaper priced Tesmart HDMI KVM switch but returned it because it did not work well with all of my mac computers (4 in total including my wife's 2013 MBP and another 2014 macmini). The display kept flashing every 10 seconds.*Update - May 20, 2020*I bought the Cable Matters HDMI to DisplayPort Adapter (includes an active monitor converter) and now my BI320 and macmini both work with the GCS1904. So I changed my 4 star rating to 5 star since I needed the right adapter for these to work properly. So the only con is the delay when switching but it's not that big of a deal since I don't constantly switch between computers.

We had to try three IO Gear KVM switched to finally find this one able to handle switching between PCs with Displayport connectors and other PCs with VGA connectors. We finally did and it works...Advice to IO Gear compatibility needs to be specified more clearly.

Did not output video signal and no response to hotkeys from my keyboard.