StarTech USB 3.0 to 4K DisplayPort External Multi Monitor Video Graphics Adapter - USB 3.0 Video Card - Ultra HD 4K (USB32DP4K)

I have spent the last couple of years bemoaning the fact that my MacBook Air could not use two external displays at the same time. I have tried all manner of things (or so it felt), all to no avail. I scrounged and searched the internet for something...ANYthing...to achieve my goal. Many cheaper adapters promised big but failed to deliver, and I managed to amass quite a collection of useless bits and bobs that sat in a bin in my storage closet.The other day, after having given up the search for almost a year, I stumbled across a YouTube video declaring that my woes were soon to be over, and even demonstrated to me, in very clear, easy-to-follow directions, what I needed to purchase and how to go about installing it. I thought, "Could this really be true? Do my eyes deceive me, and do I dare get my hopes up that this could work for me, too?"I balked a little at the price tag, but kept reminding myself that my journey to find a way of having two large-screen external monitors had been a long and fruitless one. I pulled the trigger, delighted in the fact that I would soon find out if my latest sojourn into Monitor Driver Hell could potentially be over in the next 24 hours...When the Amazon delivery driver pulled up in front of my house a little bit ago, I literally met him at the door, such was my excitement. I came inside, ripped open the box, pulled out the adapter, went to Startech.com to find the driver I needed, and followed the instructions accordingly at installation. When my trusty MBA notified me it was finished, I grabbed the dongle, plugged it into my USB port, plugged in the HDMI cable to my secondary monitor that had spent all this time feeling left out of the mix because it wasn't connected to the same laptop, and magic happened: the screen came to life with an exact replica of my other screen! (This isn't what I wanted, and I had to go to my Settings to do some fiddling about, but I was simply in a state of near-ecstacy at the mere fact that my MacBook Air was, indeed, being displayed on two external monitors!!)I quickly discovered that my monitors were set up "backwards" from what I actually wanted (I wanted the monitor that sits directly in front of me to be my Primary display, with my second one used for moving windows out of the way but still remain open on the Secondary display), which involved a very easy fix: unplug the two HDMI cables, switch them around, and done! Next I unticked the box that says, "Mirror Display" so I could free up all those wonderful pixels of newly-found desktop real estate, and I swear I heard angels singing in exaltation!At last, I have joined the throngs of users that have two large, high-quality external monitors connected to their Mac notebook, with my notebook completely out of sight and no longer taking up valuable space on an already-smallish desk - and I feel like I just won some sort of prize. (I paid for the prize, sure, but nonetheless, I feel victorious at long last!)If you're on the fence about splashing out a bit for a dongle, this is NOT the one to second-guess yourself on. DO IT! You, too, will be singing Startech's praises for the foreseeable future!

I took a risk on this and was delighted to find that, after downloading and installing the Ubuntu drivers from the manufacturer's website, I was able to get this to work on Linux Mint without any issues. My guess would be it will probably work for most Debian-based systems.

OLD review: Pretty much unusable with a 2012 Mac Mini running OS X 10.8.5 and Seiki 40 inch 4k display. It manages to display at 4k, but often flickers or drops out for seconds at a time.REVISED review (2015.2.25):Still may be early to tell, but I've revised my rating to five stars since it looks stable after utilizing a different hdmi cable. I originally used the cable which came with the Seiki, but after switching to another cable I had on hand which is 4k rated with chokes at both ends, it works!Pros: it just worked. No OS X patch necessary, no SwitchX, etc.. Again, this is with OS X 10.8.5, which came with the Mini and is the latest pre-Mavericks OS X release.Cons: Firefox is unusable [revised again, see below]; its pages do not refresh, I have to move the whole app window in order to refresh the page in view after scrolling or clicking a link. I'm not going to take off a full star for that, as Safari, Xcode and other apps appear to work fine. I may have to revise this review down if other apps don't work properly, but for now it's five stars.As far as I know, these cons only apply to OS X 10.8.5 with DisplayLink firmware version 2.3. The product release notes claim that earlier OS X versions (10.6 and .7) are not supported at all and that later OS X versions (Mavericks, Yosemite) have limitations (e.g., "[they do] not correctly support virtual frame buffers").REVISED review (2015.10.15):Still working, this time I'm using it with an old Windows 7 laptop, but I've again had troubles with screen blanking, even when using my "best" hdmi cable. I bought several, all were rated 4k, all had issues, until I bought a StarTech.com cable. StarTech.com HDPSMM1M Pro Series Metal High Speed HDMI Cable It's perfect! No red dots.Also, regarding the 2012 Mac Mini, I upgraded to Yosemite OS X 10.10 and the StarTech.com usb 3 4k adapter still works fine. It also works with that Mini running Windows 7 in bootcamp.This is not a fast adapter for 3D but I have no issues running Visio, Office, Matlab, etc..ALSO, regarding Firefox on OS X, it works! I had to configure Firefox to use software rendering, as pointed out by StarTech.com support. Yes, StarTech.com actually provides technical support.