StarTech.com SV431DVIUA 4-Port DVI USB KVM Switch with Audio and USB 2.0 Hub (Black) 4 Port

Excellent, just what I was looking for to use a central 27" monitor, switching between a mac mini and any of the family macbooks. This set allows us to have a set computer (mac mini) for anyone's use in the office, but also making any of us able to hook our laptops and that way have us ethe main monitor as a second, larger one.

I've been using Startech's two-port mini-displayport KVM for several months. It's indeed capable of 3840x2160@60hz (in and out), including G-Sync. Spec-wise, this thing ticks off all necessary boxes (though it's confusing why Startech went with mini-DP form factor here). That said, I've had horrendous issues with this unit randomly blacking out the monitor output, sometimes constantly, all without any conceivable reason. I'm fairly sure it's the box itself, and not the cables - I've tried a few, including the ones supplied, and the rate of blacking out doesn't change with cable wiggles, or more/less insertion, or otherwise, so it doesn't sound like a connection problem either. Systems are plugged into the same ground circuit so it shouldn't be a grounding problem, I'd think either? Anyway, this occurred from day one. You might also be able to go a few hours or days without your display blacking out, but more likely you'll see your poor monitor blacking on and off at random, at a rate of anywhere from half a second apart, to every few seconds, or even maybe once a minute or longer. As I said, it's quite random. Some reviewers stated this occurs only for PC2 when switched to it, and indeed it occurs more often there, but it still does occur for both PC inputs. It's quite jarring and eventually drives you bonkers and might give you a headache. That said, as a troubleshooting measure, going back to 3840x2160@24hz stops the issue. I still see the issue at 1920x1080@60hz, so I'm not sure if it's a cable/bandwidth issue. Seems like the actual KVM has some problems. So far I have not had any luck trying a custom refresh rate to see if it behaves better at 59hz or something close to that. Sticking at 24hz makes this thing nearly useless. I can't recommend this product, given the number of problem reviews complaining of similar issues, and the fact that support/RMA processes for these other users have not helped alleviate this issue (I have not tried this route myself, yet). Unfortunately there are very few alternative products for a similar price point out there, so 2160p users are going to be rather stuck waiting for a while if this isn't resolvable. I can suggest using a monitor with its own input switcher, and use a software KVM app like Synergy for keyboard/mouse switching, I guess, but my Acer XB280HK just has the one DisplayPort connector. I'm quite disappointed so far, but I'll be happy to try the RMA process in case I can add a positive result to the pile later (and update the review accordingly). I'm really not holding my breath, though. Look elsewhere if you're a 4K user, honestly.

Having used VGA KVMs for years, I decided that I really needed to upgrade, particularly now that I have a 4K monitor. Could not believe how expensive the DVI/HDMI/Displayport KVMs are and could never justify spending the 300GBP+ that appeared to be the mark for a Displayport one. Could also not understand why Startech do this one but their full size displayport one cannot handle 4K60Hz. Checked with them that this should work via displayport to mini-displayport cables and they confirmed it should be OK. The 1m Startech cables I bought worked great but I needed one to be a bit longer and bought their 2m one which had issues. A UGreen 2m one worked fine however. This setup works really well switching between my main PC and my work laptop. However, there is an issue (common to most Displayport KVMs) that prevents me giving it 5 stars. Basically these devices do not work like the VGA ones in that they physically disconnect the display. This causes screens to be reorganised as they disconnect and reconnect. I did discover a workaround to this however. On my PC, I take a DVI output to one of the HDMI inputs on my monitor and duplicate the screen on DVI and Displayport. The DVI one only works at 30Hz, but it's enough to keep the display alive at the same resolution. I do a similar thing on my laptop by taking a 2nd video output to a 4K HDMI headless ghost. Displayport disconnection still occurs on switching but the as far as Windows is concerned, it's the same output, just to a single or two duplicated displays. This prevents the windows from rearranging and keeps everything as it should be. So the end result is that I am switching successfully between 3840x2160 @ 60Hz on my PC and 2560x1440 @ 60Hz on my laptop

This product is pretty unique. I have a shiny 4K Dell display (Dell Ultra HD 4k Monitor P2715Q 27-Inch Screen LED-Lit Monitor ), and a desktop (custom build) and a laptop (Dell XPS9350-5340SLV 13.3 Inch QHD+ Touchscreen Laptop (6th Generation Intel Core i7, 8 GB RAM, 256 GB SSD) Microsoft Signature Edition ) that I wanted to hook up to that monitor via DisplayPort (mini or regular). I also wanted the connection to support a 60Hz refresh rate. This KVM switch is the only product I was able to find that supports such a connection. I believe that the regular DisplayPort version of this product does not support 4K at 60Hz, though I have not used it to verify. I can say that the Mini DisplayPort version does, however. I did have some issues getting this KVM switch to work. I hooked it up to the desktop without issue, but I immediately ran into problems hooking it up to the laptop. The Dell XPS 13 9350 does not have a DisplayPort connection, mini or otherwise, but it does have a USB-C port that theoretically supports such a connection via an adapter. I started out with this adapter (Cable Matters USB 3.1 Type C (USB-C & Thunderbolt 3 Port Compatible) to DisplayPort Adapter in Black ) and a Mini DisplayPort cable I purchased separately, but couldn't get a video signal to go through. I tried another cable, and still got nothing. Finally, I tried the cable that was included, along with a DisplayPort to Mini DisplayPort adapter, and the display worked, sort-of. Every 60 seconds or so, the image would jump. So, I tried connecting to the other port on the KVM switch, but that resulted in an unusable image. So, I bought and tried a different USB-C to DisplayPort adapter (VisionTek USB 3.1 Type C to DisplayPort Adapter (M/F) - 900817VisionTek USB 3.1 Type C to DisplayPort Adapter (M/F) - 900817 ). This one did not work for me at all. However, any and all of these combinations work fine when directly connecting the laptop to the monitor. I called tech support, and the guy I got was great. I'd already tried most of the ideas he had, but he certainly knew his stuff. Eventually we concluded that there was no single point of failure causing the issue, and that my laptop and the KVM switch simply have issues maintaining a stable DisplayPort connection. I lived with the occasional picture jump for a few days, and finally decided I should try connecting through a dock instead. I had been meaning to try out Dell's Thunderbolt Dock (Dell Thunderbolt Dock with 240W Adapter (R3YYP) ), despite its bad reviews, though I was planning on waiting for a bit to see if the issues worked themselves out. The jumpy picture accelerated my plans though, and I bought the dock. I received the dock and hooked up everything. While the dock is not without its own issues, I was finally able to get everything working smoothly, including this KVM switch. Given my unique setup, I can't really blame any of the issues I encountered on this KVM switch. The only other annoying oddity I encountered is that the KVM switch does not, in some situations, automatically switch between the two computers when one is powered off. Many desktops provide power to their USB ports when turned off, and this messes with the switch's ability to automatically switch to the other computer. In some cases it may be possible to turn off the power to the ports via a BIOS setting, but in my opinion this isn't something that should have to be done. Also, once the "active" computer is powered down, the hotkey switch no longer works, which means you have to hit the physical switch to toggle to the other machine. Still, I would certainly recommend this to anyone looking to get a 4K monitor operating at 60Hz hooked up to two machines, despite the slight annoyance I mentioned. If only StarTech had an offering that supported two 4K monitors at 60Hz!

This KVM switch has a much underplayed feature: supporting Displayport MST. This means that you can with this _single_ switch support up to four[1] 1080p displays, using a single set of cables. I have 2 Dell U2414H monitors hooked up to this switch and both my laptop and PC with no extra components. With my old (and far more expensive!) StarTech SV231DPDDUA dual head dual computer displayport kvm switch (pictured), I needed 3 displayport cables for each individual monitor, producing an enormous mess, and I had to use an MST hub to split my graphics card's single DisplayPort output into two. That said, there are downsides. the SVP231DPDDUA can use the keyboard to switch, meaning I can press CTRL-CTRL-1 and CTRL-CTRL-2 to switch between machines, and just hide the switch. You can only do this with this device if you install their awful app, which of course only supports some versions of Windows and MacOS and adds an irremovable green pea icon to your tray. The second downside is that the USB ports are on the front. This means that if you put it on your desk, there's a mess of cables in front of it where your keyboard and mouse cables are bunched up in front of it. Overall, supporting MST is a huge boon, enough for me to give this a nearly perfect score. I feel like STARTECH might be downplaying the importance of supporting MST because, honestly who is going to buy a 4 port KVM for £500 when you can buy this for ~£95 and have eleven less cables to plug in? Other than MST support, this product is mostly a downgrade from the fairly old SV231DPDDUA, and the newer SV231DPU3A (which supports USB 3.0 and is a much more attractive device, though it only works if you use one monitor since there's no MST). PROS: - Supports MST / Daisychain! - Much, much cheaper than KVMs which do similar things CONS: - It lost hardware keyboard switching support; need to install an app - USB on the front which makes for bad desk cable management - It's fairly ugly compared to some of their other new switches - No sound - No USB 3 I've attached a picture of my setup as of now. Pictured is my old KVM. The new one is under the desk. On daisychain support: - you must have a newish graphics card, see [1] - you must have monitor(s) supporting daisy chaining - MacOS appears to have daisychain disabled except for on apple made monitors, to stifle the competition [1][...]