Belkin’s Flip-DVI-D: too good to be true?

I was excited to learn recently about a new product from Belkin, the Flip-DVI-D. This little device allows a user to control two computers via a single mouse, keyboard, and monitor. I use keyboard/video/mouse (KVM) switches routinely in Damage Labs, and they’re very convenient for my purposes. My decision to buy a 30″ wide-screen LCD for our graphics test systems, though, created a problem: there just aren’t many KVM switches out there capable of passing through a dual-link DVI video signal. In fact, I’m aware of only a few made by Gefen. Those are ridiculously expensive (in the neighborhood of $600 for a four-port switch) and have gotten poor reviews for basic functionality. I wasn’t about to drop that kind of cash on an iffy product, so I was seriously considering another alternative. HP now sells a 30″ LCD that comes with three DVI inputs and can switch between them. I’d almost rather pony up the $1300 or so for this monitor than $600-something for the Gefen switch. At least then, you’re getting a nice display for your money, as well. The expense isn’t hard to justify given the amount of lab time we can waste by running only one GPU test rig at a time. Some of our tests, like scripted 3DMark benchmarks, can be run concurrently on multiple systems. Given the breadth of hardware we test, we’re talking about saving hundreds of hours in a month or two, merely by moving from one active test system to two.

That’s still not exactly a cheap ticket to a simple input-switching capability, so before I pulled the trigger, I decided to look around once more online to see if any new DVI-D KVM switches were available. That’s when I discovered the Belkin Flip-DVI-D. This cute little device seemed to be tailor-made for our needs: it’s a dual-port switch that handles four kinds of inputs: USB keyboard, USB mouse, analog audio, and—gloriously!—dual-link DVI. Belkin claims to have designed it for users of Apple’s 30″ Cinema Display, a cousin to our Dell 3007WFP. Best of all, it was only $125 at Dell’s online store. Sounded like a no-brainer to me. Belkin is a big name brand, so surely the quality would be there, unlike the quirky Gefens. I ordered one on the spot.


The Flip DVI-D. Source: Belkin.

When the Flip-DVI-D arrived, my first impressions of it were positive. The design of the device is slick and sensible. The cables needed to connect it to the two computers come permanently attached to the unit, so there’s no question about needing to buy cables separately (a frequent gotcha with KVM switches) or what plugs in where. You can then hide most of the cabling mess behind the desk, because a separate remote control unit houses the one button needed to switch between computers. This remote also houses a single LED that glows either green or yellow, indicating which computer is selected. All of this makes perfect sense, with no unnecessary complications.

When I fired up the computers connected to the Flip-DVI-D, however, my hopes for this product were quickly deflated. The Flip-DVI-D fails quite visibly at its primary mission: passing through a DVI-D signal from a computer to a monitor. The video signal just doesn’t make it to our Dell 3007WFP display intact. At best, the screen is readable, but has quite a few flashing and discolored pixels distributed around it. At worst, the video signal drops out, and the screen goes black. Sometimes, the thing will go from bad (but usable) to worse (black screen) while you’re using it, for no apparent reason, and never recover.

I found complaints about this exact problem in a user review of the Flip-DVI-D at Dell’s website, so I knew I wasn’t alone, but I was determined not to give up hope too soon. I tried a whole range of different video cards to see if that affected things, and I found it really doesn’t. Some video cards seemed to be worse than others, but the Flip-DVI-D didn’t pass through a clean signal from any of them. My next step was to order a 3′ DVI-D cable from Newegg, to see if that would help. Perhaps the longish cable that came with the 3007WFP combined with the Flip-DVI-D’s cables added up to too much length and too little signal strength. If so, a shorter cable might do the trick, right? Nope. The 3′ cable was no help at all. It may even have been a little worse.

To date, I’ve found no solution to the Flip-DVI-D’s video signal problems, and I’m not sure what else to try. I confess that I’ve not been through the motions with Belkin tech support, but I’m not optimistic about their ability to fix such a fundamental problem on a closed-box device.

This thing is less than ideal for other reasons, too. The switch is evidently not compatible with HDCP, for one. I wasn’t able to play back HD DVD movies on a PC attached to it. Also, switching between inputs involves a long delay—five to ten seconds, at least, sometimes longer—before the PC figures out that the keyboard and mouse have been reconnected. USB KVM switches seem to be inherently pokey about control switching, but the Flip-DVI-D is inordinately slow even for a USB KVM switch. Drives me crazy.

So I guess you could say my experience with the Belkin Flip DVI-D is pretty much a total failure. I love the product concept—an affordable, easy-to-use DVI-D KVM switch with a snazzy design—but the execution kills it. The thing just doesn’t work right.

Comments closed
    • pughwe3000
    • 11 years ago

    I invested in a new desk and monitor at about the same time. My graphics card had dual DVI out, so I figured I would keep my old CRT around to play games on or whatever. Well with the way it is setup, the CRT’s VGA cord needed to be about 2 feet longer to reach the back of the computer. So I went to the store, got a VGA extender, which happened to be a Belkin, it also happened to be about 10 – 15 dollars I think too. I plugged it in, and everything was blurry/doubled. Basically I had my cursor, and then to the right of it by a couple pixels was it’s twin/shadow. This happened on everything. I checked connections, then gave up. So I went onto a website and decided to order a couple different ones (male > female VGA extension cords). I ordered 2 of them, for under 10 dollars with shipping. They arrived, first one I plugged in worked perfectly.

    For the tl;dr: Belkin, has given me some crap cables in the past too. I have a couple Belkin surge protectors that I assume are pretty decent, but I am not a huge fan of Belkin.

    • h4rb1ng3r
    • 12 years ago

    Apparently Belkin tell me that this issue was related to those monitors signaling and has now been fixed. (Well for the revised model that is about to be released here in Australia shortly anyway.)

    Have you followed up Belkin yet? The review said Belkin has not been contacted. I work in IT retail and their after-sales support is exemplary.

      • Damage
      • 11 years ago

      Yes, I got an RMA and the new one had the same exact problem.

    • Resomegnis
    • 12 years ago

    From personal experience I’ve used quite a bit of the Belkin Flips. Comes in handy when setting up a nice work station. But I found that they were more useless then usefull:

    1) For some reason one of the cables is extremely short so it’s hard to manuver it accurantely.
    2) Used one, two days in the button wouldn’t work. Swapped it, new one the button wouldn’t work, swapped it again, one of the VGA cables was defective and the second screen was always Blue two weeks later button stopped working.
    3) Occassionally they have problems where one will steal the signal and even when you try to switch it will go right back to the one you were just on.

    Personally I think it’s a nice design they just have crap for hardware.

    • gmerin
    • 12 years ago

    Don’t think yours was a uniquely defective unit unless the entire production run was defective: I just went through three units from different retailers, all with the same issues. The Flip apparently just can’t handle the task (feeding an Apple 30″ CinemaDisplay). It’s almost as if Belkin didn’t actually test a production unit to confirm that the delivered devices matched the design specifications.

    I’m very disappointed with Belkin: I’ve come to expect better quality from them.

    • ioport
    • 12 years ago

    Compatibility problems are one the reasons why I sold 30″ screen and got a 27″ instead.

    That being said handling of HDCP and HDMI connections is still a problem, as I have a Blu-Ray laptop connected to a DVI KVM.

      • redpriest
      • 12 years ago

      It *is* possible to do HDCP over Dual-DVI – ATI’s latest graphic card shows that. A shame it just doesn’t outperform the 8800 GTX outright, otherwise I’d have two of them in my system at the moment.

    • gimp90
    • 12 years ago

    I have the Belkin Flip DVI-D and it works great. Im using it with a HP 30″ lp3065 monitor. I did have problems with DVI-D cables and the 3 inputs on the HP. When I switched inputs on the monitor i got nothing but a black screen. So I tried the flip.

    It works great!

    • gimp90
    • 12 years ago

    I have the Belkin Flip DVI-D and it works great. Im using it with a HP 30″ lp3065 monitor. I did have problems with DVI-D cables and the 3 inputs on the HP. When I switched inputs on the monitor i got nothing but a black screen. So I tried the flip.

    • lucas1985
    • 12 years ago

    HP seems to have the upper-hand in connectivity among 30″ monitors with the LP3065.
    However, the Samsung SyncMaster 305T seems to have the best image quality according to a TrustedReviews’ article:
    §[< http://www.trustedreviews.com/displays/review/2007/05/23/Samsung-SyncMaster-305T-30in-Monitor/p1<]§

    • Dposcorp
    • 12 years ago

    q[http://h10010.www1.hp.com/wwpc/us/en/sm/WF06a/382087-382087-64283-72270-444767-3297215.html<]§ Heck, if you dont want to be out the entire $1300, then sell the Dell and recoup a lot of that cash. If this is used mainly for benching and testing, that is what I would do. Even if the Dell is actually a nicer monitor with a nicer picture, I would rather have 3 rigs running at that super hi-rez and hitting the benchmarks then waiting for one at a time.

      • Usacomp2k3
      • 12 years ago

      So only one of the DVI input supports HDCP. That’s lame.

        • titan
        • 12 years ago

        Well, I think they’re thinking that you’re only going to use one source that requires HDCP. Though, I do agree that it probably wasn’t the wisest move. People who don’t read the manual closely will lose out on a bunch of resolution in their movies.

          • Usacomp2k3
          • 12 years ago

          Well for the purposes of Scott’s testing, it would be fine when benching games, but he’d have to be a little more particular when benching movies.

    • flip-mode
    • 12 years ago

    You could try a single-link DVI cable at a low resolution just for fun. If you call that fun…

    • SuperSpy
    • 12 years ago

    Am I the only one wondering why I got a “new news” email about this post?

      • Usacomp2k3
      • 12 years ago

      The blogs go out via the news AFAIK.

      • gratuitous
      • 12 years ago
      • Inkedsphynx
      • 12 years ago

      My first thought?

      Why would I spend 750$ on a KVM when for that I could buy another monitor/mouse/keyboard? Hell, if I was buying something small-ish, like a 22 or 21″ WS, I could buy *2* sets, if not close to 3 sets for 750$. I’d certainly think one would get much more mileage from an additional 2 sets of monitor/keyboard/mouse than a KVM.

        • Usacomp2k3
        • 12 years ago

        Desk space?

          • Inkedsphynx
          • 12 years ago

          I wouldn’t think that’d be a big concern in a professional lab environment.

          Hell, it’s not even a concern for me at home, where I could find ample space for 3 or 4 large monitors if I wanted.

          Not saying that it wouldn’t be a concern for everyone, but damn, for 750$, buy yourself another K/M/M, and a bigger desk.

      • DASQ
      • 12 years ago

      And that’s the real trick of it.

      The KVM switch is convenience, not a need. $750 is not worth the convenience of a ‘perfect’ KVM switch. For $750, you could buy another monitor, keyboard, mouse, desk keyboard tray, and a nice pack of cold ones.

      It doesn’t matter how good your blatant sales opportunity performs, it can’t be $750 good.

        • My Johnson
        • 12 years ago

        I fail to see why the extra spleen is needed in response to Richard’s original comment. I found his post to be rather professional.

          • JJCDAD
          • 12 years ago

          I agree with My Johnson. *snicker*

        • tu2thepoo
        • 12 years ago

        So if an employee of a company discloses his affiliation, it’s a blatant sales trick. If he or she doesn’t, it’s another sleazy advertising tactic.

        Nobody can win for losing around here, i guess.

      • FireGryphon
      • 12 years ago

      I think this product is aimed at serious professional places, like laboratories or places that need specific functionality and can afford such an expensive item more than they can create an alternate hardware arrangement. The problem (at least from an enthusiast standpoint) is that at $750, these are the only customers who will purchase the KVM. Enthusiasts aren’t used to paying more for an add-on than they are for the original hardware item itself. It’s still interesting to know of these things, though.

      It reminds me of the super-hi-fi audio industry, with special wooden knobs and elevated cable cradles that are fine tuned to prevent interference and ensure the most accurate sound possible. Few people can afford such products, fewer actually need or want it, and the only places it’s really required are in the most high tech labs in the world (and even then, many renown science labs that produce world class research use standard equipment).

        • Taddeusz
        • 12 years ago

        The $750 KVM and “hi-fi” audiophile hardware are totally different. One is a product that fills a specific need the other is pure snake oil.

        Wooden knobs, pure snake oil. Multi-thousand dollar interconnect cables that can be electrically proven to be no better at transmitting audio frequencies than your standard $5 Radio Shack special, pure snake oil. Couple thousand dollar power cords, pure snake oil. These aren’t products that that fill a specific technical need but fill the desire of people that not only have too much money but truely believe that these snake oil salesman provide products that make a substantial difference in the “new emotions” that their overpriced products bring out in their audio experience. If you’ve ever read the marketing literature for some of these products you’ll see what I mean. They list little to no technical detail about the products they’re peddling but have all this feel good nonsense to make prospective buyers feel more at ease about giving up several thousand dollars for often times far less than $100 in actual parts. Even Bose is guilty of this even though they are the least of the offeders.

        A quality DVI KVM is not at all like the snake oilism of high end audiophile audio.

          • FireGryphon
          • 12 years ago

          I didn’t mean to compare the usefulness of the products, but the size and nature of the market to which they both appeal – namely, a very small, very ‘elitist’ group of people who want such a specific thing that they’re willing to part with an inordinate amount of money to get it.

      • murfn
      • 12 years ago

      I am trying to figure out why a KVM switch needs to be so expensive.

      Both the mouse and the keyboard are USB so they can be unplugged on the fly. So that part of the switch is a simple breaking of a circuit. And my computer will keep working quite happily while I turn the power on and off on my LCD. Which means that can also be a simple switch. The LCD link is non-DVI though. But I am sure you can switch your monitor off while the computer is on even with DVI.

        • JJCDAD
        • 12 years ago

        Maybe I don’t understand what “dual-link DVI” is. But why can’t a person use a USB switch + HDMI switch in conjuction with DVI-HDMI cables? Seems like that could be done for ~$100. ?

          • Usacomp2k3
          • 12 years ago

          HDMI specs don’t provide enough bandwidth to run the full resolution of the 30″. Neither does a single-link DVI. Hence the need for dual-link DVI.

            • JJCDAD
            • 12 years ago

            Thanks for the clarification.

        • Taddeusz
        • 12 years ago

        This is because it’s more difficult to switch digital signals while keeping signal quality intact than it is to do the same thing and maintain a usable analog signal. The analog signal can have some loss and still be quite usable while the digital signal can have no loss to keep it usable.

        Particularly when you’re talking about parallel signals such as the seperate red, green and blue digital data feeds that go over DVI. The timing must be kept in sync or else the image may not display correctly. Or if there is enough data loss it may not display at all.

        An analog signal such as standard VGA doesn’t suffer from this problem because even a degraded signal can still be usable. Sure it may be blurry or ghosted but you won’t get total loss of the picture.

          • murfn
          • 12 years ago

          You bring up 2 issues. The first being signal quality, and the second is keeping the frames in sync.

          As to the first, why would the signal quality degrade to such an extent by simply switching the source?

          As to the second, the monitors must have some recovery routine when the signal is temporarily lost. This happens when you switch off the monitor, turn off the computer or change resolutions. Changing resolutions and switching on the computer could be handled neatly, but switching on the monitor can happen at any time in a frame.

            • Taddeusz
            • 12 years ago

            The signal doesn’t degrade by simply switching the source but because of the extra circuits the signal must pass though in order to reach it’s destination.

            A normal DVI or VGA connection is a straight length of multi-wire cable from the computer to the monitor. Because of the extra ciruits in a KVM this usually causes noticeable degridation is signal quality in VGA KVM’s. A VGA KVM can be made quite cheaply and still maintain a quite usable picture. The degridation is an acceptable tradeoff for the convenience of being able to use a single monitor for multiple sources.

            A DVI KVM must clock a digital signal through perfectly with no loss while keeping the ability to swtich between two or more sources. *[

            • murfn
            • 12 years ago

            There may be a technical explanation for what Richard Cawdery was saying, but I am still sceptical about yours. Some KVM switches are designed to switch between your desktop PC and the server in the computer room. In such instances there is significant signal degradation because of the distance. Whatever circuitry is included in the KVM switch it should have a limited effect on signal quality. It is not like the signal is split. And unless the KVM switch does some sort of image processing, like picture-in-picture, I do not see why such circuitry has to be complicated. Simply route the source of choice to the destination.

            While a digital signal will result in total loss with even a small amount of error, the loss will occur only when the signal strength drops below a certain threshold. Otherwise, the picture will be perfect. This is the advantage of digital.

            • Taddeusz
            • 12 years ago

            You obviously don’t remember the old mechanical KVM switches. I’ve seen some pretty nasty looking results from those back in the day just running basic 640×480 or 800×600. I’ve seen similarly bad results from today’s solid state KVM’s but nowhere near as bad as the old mechanical type. The reason you get loss is due to the fact that the signal is leaving the confines of the shielded cabling long enough for other sources, including the other parts of it’s signal, to induce noise.

            You’d think digital signals would be simpler but they key is that the device must be able to maintain a stable “on” voltage and be able to switch from “off” to “on” and back to “off” at least as quickly as the incoming signal without distorting the leading and trailing edges of the bits. It’s not as simple as the relatively continuous wave that you get from an analog signal. If the signal isn’t clocked correctly you might get zeros that are taken as ones or visa versa. Or maybe the overall signal doesn’t have enough amplitude to have the ones taken as ones. And because DVI contains no error correction the signal must pass perfectly to be usable.

            • murfn
            • 12 years ago

            What you are describing looks to me like an amplification process. You are taking a signal, and creating an identical but amplified signal. That would be more complicated. The very throughput of a digital signal depends on how quickly you can cram ‘0’s and ‘1’s together. I am talking about routing the original signal. Are you saying that any such routing would result in a fatal degradation of the signal because the device could not possibly shield the signal, assuming no amplification effort is taking place?

            gimp90 reports the Belkin KVM as working. Presumebly, his KVM switch is identical to the one used here. Going with your explanation, his setup would work because either because his GFX cards produce an unnaturally strong signal or his monitor can deal with erroneous signals.

            • Taddeusz
            • 12 years ago

            Passing the signal through the extra circuits of the KVM is going to reduce it’s amplitude by a little bit. This may not make a huge difference for an analog signal like VGA but can make or break a digital signal such as DVI. Particularly because DVI contains no error correction.

            • murfn
            • 12 years ago

            I really would like a proper explanation on this issue. It is now Tuesday and some input from the working folks at Belkin should be made available. Your explanation seems unsatisfactory to me. The DVI specs require the signal to be strong enough for a 5m cable. I find it difficult to believe that this device was designed so poorly as to degrade the signal over a distance of no more than 1.5m, up to a point where it is marginally clean enough for reception.

            Nevertheless, the signal strength theory can be tested. A Google search supplied info on the CDL Micro DVI-D Dual Link Repeater/Extender/Booster. If available it suggests that two boosters can be had for about $100. Placing two boosters between the computers and the KVM switch should resolve all degradation issues.

            • just brew it!
            • 12 years ago

            Any time you have additional connectors, switches, or other devices in the signal path, you will tend to have an impedance mismatch. At lower frequencies, this doesn’t matter much. At higher frequencies, it causes signal reflections and ringing (where the signal takes some time to settle down after a transition). The signal in a DVI cable is switching at roughly 10x the rate of the signal in an analog VGA cable; reflections and ringing which would merely result in a little blurring or ghosting on an analog monitor will completely obliterate multiple bits of data on a DVI link.

            When dealing with signals in the gigahertz range (as DVI does), interference (crosstalk) between circuits due to capacitive coupling is also a major concern. The R, G and B signals within a DVI cable are each run as a “differential twisted pair”, which minimizes the crosstalk between them. But in order to run the signals into (and out of) a cheap switch, you’re probably going to break the twisted pair arrangement as the signal passes through, in the name of keeping the device simple and inexpensive. So the switch probably adds some crosstalk between the R, G and B signals as well.

            Add these effects together, and is it any wonder the monitor just can’t make sense of the signals any more?

            It’s not just a matter of signal strength; it is a matter of signal /[

            • TO11MTM
            • 12 years ago

            Here’s some math for the sake of this discussion.

            Each DVI link operates at up to 165MHz, with 10 bits of data. That gives you theresabouts 1.65Gb (Gigabit, not gigabyte,) per second.

            Methinks something like a Spartan-3 or other FPGA should be able to handle this without much work. The trick would be to program it… that said in decent quantities a total price of 200$ should be doable.

            In fact, Xilinx touts the Spartan-3 as being great for use IN displays as the main video processor. Surely if it can do that it could handle forwarding the signal to A or B.

      • gmerin
      • 12 years ago

      You write as though the problem is with the consumer.

      If it’s not possible to produce a working product at the lower price, then the manufacturer shouldn’t produce the a marginal product at that price at all. It’s not the consumers’ fault for attempting to get what they need at the lowest cost possible: that’s how supply and demand works.

      If the cost of a functional KVM exceeds the cost of a second display, then the manufacturer shouldn’t realistically expect to sell the KVM.

      If Belkin can’t produce a functional product for the $150 MSRP then they shouldn’t produce it at all. If they advertise a non-functional product, that constitutes fraud.

    • Spotpuff
    • 12 years ago

    Watching it crash and burn was great.

    • Krogoth
    • 12 years ago

    Are you sure that KVM supports dual-link DVI-D output?

    I suspect that the Belkin KVM only has single-link connectors which is hopefully inadequate to feed your 30″ Dell LCDs at their native resolution. The experiences that you are describing clearly show that the monitors weren’t getting the sufficient bandwidth.

    I think that you might have been cheated if the specs “claimed” dual-link support.

      • Damage
      • 12 years ago

      Yeah, amazingly, I read the specs. 😉

        • Krogoth
        • 12 years ago

        I think you were cheated. The problems are signs of insufficient bandwidth. Have you try to revert to resolutions, refresh rates that single-link DVI is known to handle fine?

          • Damage
          • 12 years ago

          Lower resolutions have the same problem.

            • Krogoth
            • 12 years ago

            I guess you ether got a defective unit or the design is just flawed.

            In any case, I guess it shows that you get what you pay for. 😉

            I am not surprise that a *[

            • Jigar
            • 12 years ago

            You dont give up do you?? 😉

    • Usacomp2k3
    • 12 years ago

    Have you found any DVI-D switches without the KM part of the KVM?
    Keyboards and mice can be got quite cheaply.

    • JJCDAD
    • 12 years ago

    Sounds like a painful experience. Too bad for you. 🙁

    BTW – when I first saw the picture I thought you were reviewing some baby’s teething toy or something. :/

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