DVI/USB KVM Switch Issues

April 2, 2005

Our story thus far… About a year ago, I purchased a Belkin DVI/USB KVM switch.  It worked alright, and a few months later I posted a brief review of it..

(A brief aside—what’s a DVI-USB KVM switch? A KVM switch is a device to switch a single Keyboard, Monitor (the V is for video) and Mouse between multiple computers.  DVI is a standard for digital interfaces to (usually) LCD monitors, a more accurate (hopefully) alternative to analog VGA.  Mice and Keyboards used to use their own interface, but now are often USB based.  So a DVI-USB KVM switch is meant to switch a DVI-based monitor (usually LCD), and a USB keyboard and mouse between multiple computers)

It turns out that I’m about the only one who seems to have had any luck with the Belkin unit.  Since last summer, the post has received nearly a hundred comments discussing the multiple problems people have had with these units, some competing units, and problems with those.

It seems that making a good working DVI switch is a lot more problematic than making a VGA unit.  This is reflected in the price, too—low-end VGA KVMs (even USB versions) can be had for around $20 – $30; the DVI units start at about $175 and go up—sometimes way up.

I’m starting this new post for two reasons.

First, there is a lot of good discussion going on on the old one, but it’s getting very long (and probably slow to load for those on slow connections)—I wanted to add a new post and continue the discussion with it.

Second, my luck with the Belkin unit (maybe I got one of the few that ever sorta worked right?) ran out yesterday.  It lost it’s little mind, doesn’t switch, and just beeps continuously.  Since I use the unit to switch between my Powerbook (my normal working machine) and a desktop PC I use mostly to check that web sites work properly in Internet Explorer and to process a little video, I’m rather stuck for being able to use the PC at the moment.

Obviously, I won’t be getting another of these units (in fact, I don’t think they’re available right now), so my choice is between one of the three or four competitors that everyone has identified and…

Doing without.  It’s pretty clear that the state of the art in DVI KVMs has a ways to go.  Not only that, but a reasonably well-functioning 17” DVI LCD monitor can be had for right in the same price range as a new switch.  If I can find the desk space, I could add one of those for the PC, keep using my 19” LCD for the Mac, and pick up one of the $20 – $30 VGA KVMs to switch my keyboard and mouse back and forth (leaving both monitors running all the time).

I could go that route, give the KVM switch manufacturers a little time to get their act together, and look at going back to a fully switched system down the line somewhere (I can always find someplace to put a 17” LCD.)

Has anyone gone this route yet?  Any issues with using a VGA KVM without the monitor?

Alternatively, does anyone have anything really nice to say about any of the competing units?  There has been some back and forth on several, but no really glowing reports that I recall…

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82 Responses to “DVI/USB KVM Switch Issues”

  1. Chuck Lawson on August 9th, 2005 8:59 pm

    > can anyone give me a recommendation for a simple USB switch?


    I’ve been quite pleased with this one.

  2. Tom Degremont on August 17th, 2005 7:56 pm


    Thanks for your informative posts…. I’m a little confused about the way you are recommending to disable the power management feature for the IOGear (I have the GSC1762). I have a mac and a PC. If I boot in the PC, everything works fine. I can then switch to the Mac. Only problem there is that the mac believes there are 2 monitors (my ACD and a VGA monitor which I assume is IOGear emulation). I can work on my mac, but this other monitor showing up on my desktop is annoying. If I then switch over to the PC again, I get a black screen. Nothing there. I am thinking that perhaps it has gone to sleep, and can’t figure out a way of waking it up again…

    any ideas?


  3. Frido on August 18th, 2005 4:46 pm


    Surprised the comments are still active, this must be the biggest dvi-kvm resource on the net by now 🙂 Anyway, has anyone tried the new gefen 2 port dvi kvm ?


  4. Chuck Lawson on August 18th, 2005 6:57 pm

    Hi Frido;

    Actually, this is the second installment of the thread — I opened this one up when this one went over 100 responses…

    Pretty soon we’re going to need a book or something…

    – Chuck

  5. Oscar on August 21st, 2005 10:52 pm

    Ok, I’m joining the conversation… I’m surprised teh Gefen unit Frido mentioned is actually cheaper than the competition! The company has a pretty good reputation.

    I’m trying to share one of the infamous Dell 2405FPW (1920×1200) screens between my PC and a MacMini. I’d *really* like a four-port unit, but not if it means sacrificing quality.

    Given what everyone has said here so far, I’m leaning towards the Addlogix and the new Gefen.

  6. Oscar on August 22nd, 2005 1:02 am

    Neko: The Lindy switch looks to be the same as the Adder one. I’m guessing they’re Adder’s OEM. Keep in mind that this one has no USB switching (only PS/2).

  7. Piblokto on August 25th, 2005 10:09 pm

    Anyone know anything about these Purelink DVI switches sold by Pacific Custom Cable? I am still addicted to my IBM M1 clicky keyboard, so I will only surrender my PS/2 port when it’s pried from my grimy RSI-afflicted fingers. I plan to use a DVI switch (KVM or simple switch) for video, and use an old Linksys switch for keyboard and mouse. Little extra work, but I’m fine with it.

  8. S Church on August 31st, 2005 9:48 pm

    Our web site,, is currently looking at some of the “new” DVI KVM switches. As others report here, we’ve had significant trouble with the ATEN CS-1764. We believe it may be a fundamental issue with the nForce chipsets (as others said here). Also, very noisy video despite ATEN assuring me it would work at 1600×1200 on a 20-inch screen (indeed, noise is only on some; not all machines).

    We’ve just received the Avocent SwitchViewDVI for review and it looks great. No video noise, keyboard/mouse work great. We did have to plug the Logitech mouse into the USB port (versus the mouse port) to get it recognized, but seems to work fine now. We’ll post a full review/comparison within the next few weeks.

  9. Chris Harmon on September 10th, 2005 9:04 pm

    Hi all,

    Can’t believe I stumbled onto this thread!

    I’m having problems getting the Iogear GCS1764 to work with a ViewSonic VX910 19″ LCD monitor. Everything is plugged in correctly and I can always switch to the second port one time without a problem. However, when I try to switch back to the first port,, I get a couple beeps (the kind Windows plays when new hardware is detected) and then the monitor displays the “No Signal” message. The same thing happens with subsequent port switches.

    No luck with Iogear tech support so I thought I’d try here.

    Any suggestions? I can provide more details if needed.

  10. Matt Dralle on September 13th, 2005 2:16 am

    Let me guess… You’ve got an ATI video card? I’ve been having the same problem on three different Linux systems, and one Window 2000 server system. NVIDIA video cards don’t seem to have any problem. One guy above suggested using the Ctl-Alt-F1 / Ctl-Alt-F7 in Linux and this does seem to get the display working again, but it also crashed my Liunx system after a few flips back and forth. Not sure what the problem is with the ATI video cards, but again as the fellow above pointed out, getting the latest Windows ATI drivers seems to fix the problem (I personally haven’t tried that). Wonder if the latest Linux ATI drivers would help… Hum…


  11. Matt Dralle on September 13th, 2005 3:18 am

    Well, here’s a solution to the DVI vs. ATI switching problem. Use the Vesa driver under Linux instead of the ATI driver. This assumes that performance isn’t a big deal for you. The latest Linux driver I could find on the ATI web site was 8.16.20 for i386 and this version has the problem. I switch Xorg over to the built-in Vesa driver (might have to move all of the /usr/X11R6/lib/modules/drivers/*.o and /usr/X11R6/lib/modules/drivers/*.so files into a different directory and just put the vesa_drv.o file in the /usr/X11R6/lib/modules/driver/ directory, then run “Xorg -configure” and go find the file it makes and put it in /etc/X11. You’ll also likely have to add mouse configuration back into the file and I added the following:
    Section “InputDevice”
    Identifier “Mouse0”
    Driver “mouse”
    Option “Protocol” “IMPS/2”
    Option “Device” “/dev/input/mice”
    Option “ZAxisMapping” “4 5”
    This is for Redhat WS Version 4.
    Matt Dralle

  12. Andy Choi on September 15th, 2005 6:10 pm

    S Church:
    “We’ve just received the Avocent SwitchViewDVI for review and it looks great. No video noise, keyboard/mouse work great. We did have to plug the Logitech mouse into the USB port (versus the mouse port)”

    Did you try the 4-port Avocent unit? How about all 4 ports? Apparently this is the same unit Linkskey uses. I didn’t really have problems with their USB, but more so with the video on port 4.

    I think I’ll give Avocent a shot when has their 4-port model in stock. They have a very NICE return policy (it doesn’t cost you anything within like 30 days, if you get free shipping to start)

    I had issues with the IOGEAR and an ATI Radeon 9000 Mobility. The resolution would change to 1024×768 everytime i cycled a switch from/to the laptop. But other than that, no issues with a 20″ LCD (Dell 2001FP) and 1600×1200..

  13. Stux on September 16th, 2005 4:05 am

    Okay, my last post was on June 10th, when I said I would order the Uniclass KVM, which is the same as the Linkskey KVM (but the actual manufacturer)

    Anyway, I did, and It took me a month and a bit to actually get one, but its taken me a full TWO MONTHS to actually get the cables which were supposed to come with the KVM!!!

    Anyway, aside from that total cock-up, the KVM seems to work perfectly with my Apple 20″ LCD, PowerMac G5 and ATI 9200Pro based XP PC. Using the standard apple keyboard and a Microsoft Starck Mouse.

    I use the mouse+keyboard via the hubports not via the mouse/keyboard ports because I don’t care about keyboard based switching, but I do care about proper passthrough.

    Video switching is near instant and flawless

    both OSes recognise the mice/keyboard switch in a second or so, since I’ve been crawling on the ground unplugging and plugging in DVI cables for the past 4 months I am certainly happy.

    And I’ve finally gotten rid of the second keyboard and mouse, yeay.

    More long term thoughts will probably come after I’ve got some more serious experience with the switch

  14. Darren Ehlers on September 16th, 2005 2:02 pm

    I have a two computer setup:
    1) Mac Mini
    2) Dell Latitude D600 with C/Dock and ATI Radeon Mobility 9000 (w/ DVI)
    Mac 20″ Cinema Display

    I use the IOGEAR GCS1762 DVI. I have been very happy with this when working on the Mac. My MSFT keyboard works just fine using the volume, mute, scroll wheel etc. When switch on for my Latitude, the IOGEAR works perfectly as well. Drives the Latitude at 1400 x 1050 and the 2nd dispay at 1600 x1200.

    My problem is that with the laptop, when the IOGEAR is not switch to it, is forced to a 1024 x 768 resolution, which sucks. The work-around is to unplug the DVI monitor cable and re-dock.

    Anyone else have this problem? Any solutions? I have all the latest BIOS, display, etc drivers from Dell, ATI, etc.

  15. Oscar on September 17th, 2005 10:44 am

    Just a little report:
    I ended-up getting the Addlogix KVM-201DVU-2AFC with USB and FireWire support. The unit is nicely built and generally works well. There isn’t any noticeable difference between using the switch and plugging the display directly into the computer. I have it hooked up to the following:

    Dell 2405FPW LCD display
    Home-built AMD PC with ATI RADEON 9600 video adapter
    Mac mini

    My only problems (you knew these were coming, didn’t you?)…

    1. Screen will sometimes go blank for a second at the start when playing multimedia (videos) on the PC. It’s as if the unit wants to switch to the Mac, but then changes its mind. I thought it might be a power issue, so I plugged the KVM into power using the provided AC adapter, but it didn’t make a difference. This definitely never happens when I have the display plugged directly into the computer (I’ve tested by reconnecting it this way).

    2. The Mac mini never goes into sleep mode. This is true even after leaving everything on overnight. Again, this is never a problem when it’s not plugged in to the KVM.

    3. You can hear a bit of noise through the speakers when scrolling through windows (vertical scroll in a web browser, for example) on the PC. I have the audio connected/switched throught the KVM. Not a huge problem, but again, it doesn’t happen without the KVM.

    Other than that, it’s a very nice unit and very reasonably priced. It’s a little frustrating that it’s >>this

  16. Oscar on September 17th, 2005 10:44 pm

    Following-up on my own message: I take back issues 2 and 3 above. The mini seems to be going to sleep now, though I’m not sure what the change was. The noise only happens with the PC, so I’m willing to believe it’s an issue with the built-in audio chipset on the motherboard.

    The first problem is still an issue, though. Maybe a driver update will fix it…

  17. Chris on September 20th, 2005 4:44 am

    I have the aten CS-1764, got it a couple days ago, running it on a viewsonic vp200s at 1600×1200.

    port 1: windows 2k on a old nforce 2 or so board
    port 4: blank box, tried various installers

    useing old ibm modle M ps/2->aten ps2 to USB converter -> KVM. distance between desk and KVM is 20′

    so far i had the noisey video on all ports, 4 more so, but it was a 25′ cable run and reduceing it to 15+5 cables (high end) solved that for the most part (sometimes see green pixels still on full screen video), but the problem is the signal strength dropping and the data being lost some where i belive. Going to get a 3′ cable and see if that solves the problem

    port switching works perfectly. screen sometimes blanks for .5s between, but i think thats ok

    But my only problem now is on port 4, freeBSD, i get the hit key once repeat forever, but not with the debian/openBSD installers. and in windows installer i get the delayed response. installing windows now to see what happens. I figure it is the nforce chipset. But plugging it in via a hub doesn’t work

    I’m going to be getting a P4 soon, and some USB PCI cards and will see how they work with this switch. Hopefully its the nforce chipsets USB and useing a diffrent host controller will fix it.

    i’ll follow up with more once i get some mroe machines to play with here

  18. Patrick on September 20th, 2005 7:10 pm

    IOGear KVM GCS 1762 report

    Display: Aliminum Mac 23″ Cinema 1920×1200

    PC: ATI AIW 9800 1920×1200 60hz 32 bpp
    Mac: G5 1920×1200 60hz 32bpp

    Keyboard: Mac Keyboard
    Mouse: Microsoft intellimouse (wireless optical)

    Video switching:
    Sometimes, when switching to the PC, the display does not come up. “sleeping” the PC with the power switch
    usually brings it back. The video problems seem to be related to the apple display being quite finicky about the signals on the wire, or
    perhaps it is expecting the signals to come up in a certain sequence. In any case, the standby/resume seems to
    work every time, and also the display lights on every reboot. Further, simply unplugging and plugging the
    monitor directly from the PC does not always result in a successful display activation. The monitor usually acts
    like there is no signal (low intensity non-blinking light on the panel) but before I loaded the most recent ATI
    drivers I got the 3 blinks indicating out of spec signal.

    Keyboard: Sometimes the keyboard goes nuts, usually on the mac. It misses keys, is way behind the typing sometimes.
    Resetting the USB and unplugging/plugging the kbd recovers it. Sometimes on the PC a control or shift key will get
    stuck on, and the only way to recover is to switch to the mac and back!

    If you plug the mouse into the keyboard usb hub (on the back of the mac keyboard) then plug the keyboard into the
    Mouse usb connector on the KVM, then there are NO mouse or keyboard problems, but then you lose keyboard switching

    The “keyboard” usb port is special, and if you plug a mouse into it, it will not work. This appears to be because
    this usb port intercepts and attempts to interpret keystrokes to support keyboard switching and mapping.

    Using the keyboard mappting feature is a bad idea. I have tried several times and found that if you map the
    keyboard (tell it you have a mac keyboard) then it is slower and keys get stuck (like shift and control) more often.
    Also there is sometimes a perceptible lag when typing characters.

    One of the tech support people told me that if you plug the keyboard into one of the usb ports on the back of the
    KVM then you can still have the hotkey functionality. NOT!

    I see no display artifacts and am generally pleased with the device — I can live without the keyboard switching.

  19. Clif on September 28th, 2005 12:15 am

    I just picked up the GCS1762 myself and have two PCs, one with an ATI Radeon 9600 and one with a Radeon 9800. Both have problems where when I try to switch, it will often go black and my monitor gives me “no signal” and only a reboot seems to fix it. This makes the switch pretty much useless to me so I’m hoping to find a fix for it soon or I’ll have to send it back.

    It seems that if there’s a problem with ATI video cards, it’s something that IOGear should fix right away, right? Right!? 🙂

  20. Andy Choi on October 6th, 2005 9:47 pm

    Anyone else try the Avocent Switchview 4-port KVM switch (DVI)? Any success? I’m considering giving it a shot.

    Dan: I have a 600m and the D/Port advanced port replicator. You may or may not know this, but the D600 and the 600m, are practically the same machine. They have the same guts inside, and the same configuration. The diff is the shell is different and targeted customer (biz vs consumer).

    That being said, I had the exact same problem you are having. I couldn’t find a fix. Trust me, I tried everything.
    Anyone around with a laptop with an ATI graphics card and a docking station with DVI? At the time I was considering *borrowing* my docking station for my IBM Thinkpad from work and trying it on the IOGEAR, but then again, i don’t have the key to the cable lock! I have a feeling that machine with a 7500 Mobility card would show the same behavior.

    With all the issues with the ATI Mobility chips and nForce chipsets I’m AMAZED that ANY of you guys kept your IOGEAR KVM switches. I promptly returned mine! ( has a great return policy, no restocking fee and they pay return shipping)

  21. Erin on October 9th, 2005 2:32 pm

    I’m just curious about how the Gefen 2×1 DVI Switcher is behaving. There were a few comments above about people wanting to try it, and not as many comments about how well (or not) it worked.

    I only really have to get VGA working right now, but we have a DVI-ready flat panel, and would rather not limit ourselves with the KVM. The general feeling I’m getting is that DVI KVMs are unstable at best – but it looked like promising things were happening in late July/August/September.

  22. harry on October 12th, 2005 8:34 am

    just got an addlogix dvi kvm switch (KVM-201DVU-2AFC); works beautifully, not like my belkin soho switch, which can’t work with dvi-d =(

  23. Andy Choi on October 16th, 2005 12:24 pm

    Gee more bad luck:
    I tried the Avocent 4-port DVI model. Guess what? It’s just like the Linkskey model is except it’s about $140 more or so. They simply rebranded the exact same unit. Even the cables are the same (and of bad type because they are DVI-I, not DVI-D)
    The avocent model had the same video issues on port 4 as the Linkskey. My synposis: Send it back. Definitely a ripoff especially considering they are charging you so much more for the same product. I also can say that I’ve lost respect for Avocent. They may make good enterprise KVMs, but their desktop models are terrible.

    On another note, someone from Addlogix claims the 4-port model of their 2-port DVI KVM switch (the one which people seem to express the most positives about) should be out sometime in the beginning of ’06. However consider that about as unofficial as possible. Either way I think I’ll give that and shot, otherwise give up looking for now and keep what I have.

  24. Stux on October 18th, 2005 8:00 pm

    Been using my Uniclass/Linkskey KVM for a couple of weeks now.

    Works great, except for two minor problems

    1) if my PowerMac G5 crashes (rare) and I need to power it down, then power it up, the KVM won’t recognise the powemac’s USB chain until i unplug and plugin the USB chain on the back of the KVM… little bit inconvenient, but the PowerMac isn’t supposed to crash anyway and that’s much more inconvenient. Just a normal restart doesn’t have the problem

    2) When I plugged the KVM into the XP PC’s USB1 port, XP kept telling me it could run faster in a USB2 port… when plugged into the USB2 port on a PCI card, it said it was a USB2 device, and everything seemed good… except switching to the PC only seemed to work 30% of the time… the rest of the time the mouse/keyboard wouldn’t respond. This is probably either a bug in the KVM which isn’t supposed to be a USB2 device, or a bug in the cheap USB2 card. Anyway, switching back to the USB1 port, and disabling the USB warnings fixed the problem totally.

    Other than those two minor issues, the KVM has been fantastic and is a god-send.

    Note: I have my mouse/keyboard plugged into the monitor hub, which is then plugged into the KVM’s hub port. I do not use the kvm’s keyboard/mouse ports as I want *real* keyboard support. I use the manual switch buttons on the KVMs body, not hot keys.

  25. David on November 8th, 2005 8:50 am

    Hi – I came across this thread while looking for solutions to a niggling little issue with my KVM setup. Thought I’d add my experience to the pile in case it helps anyone else.

    Last month, I picked up an iogear “miniview dvi 4 port usb kvmp switch” (gcs1764). I have a wintel box, a mac mini, anda G4 cube hooked up to it. I am not using the fourth port, so I can’t speak to the issue of poor video qaulity on that port. (I had read about the issue before deciding on this box, but felt it wasn’t a big deal for me, as I don’t intend to plug another machine in anytime soon.)

    The keyboard (mac 102 extended) is plugged into the ‘special’ usb port and hotkey switching is working without any problems. The Mac specific keys (volume controls and eject) even work as expected.

    Of note: When booting up any machine, the kvm needs to be set to that port, or the display will not be recognized. After it is though, I can switch away as my heart desires.

    A summary of my setup and gremlins follows:

    Monitor: 20″ Apple Cinema HD (latest rev – aluminum bezel) 1680×1050 res.

    PORT 1: Wintel box (no nForce chipset), windows 2k sp4 (Nvidia geforce 6800)
    – no issues with the kvm

    PORT 2: Mac Mini, Mac os 10.4.3 (ATI Radeon 9200)
    – very occasionally, the mac thinks I’ve hit the brightness key when hitting the Command key (Not a big deal at all – it is so transient and fleeeting that it has only affected the brightness of the display once.)
    – (the minor annoyance I’m looking to fix) When switching back to the mini, the display has to ‘reset’ – I’m assuming that the Mac (or, more generally, the ATI card?) gets confused when the dvi signal disappears. It takes a second or two for everyting to pop back on screen, and some applications’ windows are relocated. Still usable – though if I were switching back and forth constantly, it’d be really annoying.

    PORT 3: G4 cube, Mac os 10.3.9 (ATI RAGE 128)
    – no problems with keyboard and mouse
    – would hard freeze when I had a wacom tablet plugged into the USB hub – no problems once I removed it.
    – DVI’s not hooked up at the moment. (waiting on a new vid card that can drive the cinema display’s resolution.) If there are any new issues when I do get it plugged in, I’ll report back.

    To sum up: The iogear works – not perfectly, but well enough. It supports 1600×1200 res (or 1680×1050 widescreen). The keyboard emulation has only very minor and sporadic problems on Macs (and yes, I did configure the ports for Mac support, per the manual’s instructions). There is a minor glitch with either ATI video cards or Mac OS X system software, though it is not fatal. You cannot reliably share a wacom tablet between systems.

    I think that’s pretty much all the wisdom I can impart here. Good luck to everyone else! Here’s looking forward to the day when usb/dvi kvms are plug n’ play simple (and don’t demand a king’s ransom). 🙂


  26. Andy Choi on November 19th, 2005 2:29 am

    Work around to the problematic ATEN USB and nForce4 chipsets!!!

    From here:

    “Since last emailing, I’ve tested putting a USB hub between the KVM and the nForce4 computers and this seemed to resolve the keyboard and mouse problems. Unfortunately, I need this hub elsewhere so I’m now awaiting delivery of a couple of small, cheap USB hubs to permanently sit between the KVM and nForce4 computers (they were cheap eBay sourced items so I’m happier to do this in the hope of a fix rather than possibly wait a long time until Aten come up with some answers and perhaps a new firmware). Another alternative I was considering was buying a PCI USB card for each of the affected computers and using that to connect to the KVM rather than use the onboard USB… my thinking was that this *should* fix it as it rules out any of the nForce4 USB controllers, but this would use up a PCI slot on machines that only have 2 normal PCI slots to start with.”

    Note, the very positive aspect of the ATEN KVM switches is that at least in Windows, the mouse and keyboard aren’t emulated. In fact it’s the only DVI KVM switch I’m aware of that will do this.

  27. David on November 23rd, 2005 3:00 am

    Reporting back on the G4 cube…

    I’ve had all three machines running on the iogear now for about two weeks. Things are still working well.

    I installed an ATI Radeon 7500 in the cube. Interestingly, the glitch that I see on the mini (OSX 10.4.3, Radeon 9200) doesn’t afflict the cube (OSX 10.3.9, Radeon 7500). Whether it’s a difference between different ATI driver revisions or the OS versions, I don’t know.

  28. John Mangus on November 29th, 2005 5:13 am

    Someone asked about Gefen’s new 2×1 DVI Switcher is behaving…

    Model #: EXT-DVIKVM-241-CO (cables included)

    20″ Apple Cinema Display (DVI)
    Mac mini SD (Late 2005)
    PC w/ BFG MB, Athlon64 3500+, Nvidia BFG 7800GT

    Ok… how do I start. After calling Gefen before buying this to make sure it would work with my configuration I toyed with the idea of buying the IOGear or Belkin DVI KVM switches but were not happy that the resolution was fixed at 1600×1200. So I recently purchased the above mentioned Gefen product.

    Gefen assured me that their new 2×1 DVI KVM would in fact work with my submitted config. I ordered the switch from one of Gefen’s listed dealers. Upon setting it up I too tried using the Cinema display USB hub and found that the PC didn’t care too much for it. Reconnecting the keyboard and mouse plugged into the kvm switch worked fine until I tried to start switching between the Mac mini and the PC.

    PC boot w/ monitor then switch to Mac mini (Mac mini worked flawlessly)
    Mac w/ monitor switch back to PC (no video)
    Mac boot w/ monitor then switch to PC (no video)
    switch back n forth (no PC, always Mac worked)

    Gefen suggests online with descriptions of all DVI switches will work PC & Mac. Like I said, I called gefen to confirm my configuration before buying it and they explain it would work fine. After hours of messing around with it… researching online for help, comments, forums, etc., I came accross two details that are left out from Gefen’s product page and product listing of suggested accessories for every DVI switch they offer.

    1. DVI Detective
    2. Online forum (gefen support replies) & Product manuel request additional purchase of above product to work with most DVI video cards.

    After the fact: Bottom line –

    Not happy with the Gefen 2×1 switch – it just simply doesn’t work!

    Only after buying this did I find the negative issues of DVI KVM switches. Mainly the issue that almost every brand out there is shipping a product that doesn’t adhear to DVI EDID needs; essentially “tricking” the computer into thinking that the video is present, even when it is not connected. Reading reviews, product specs, etc., the only DVI KVM switch I know to try next is from Addlogix.

    Dissappointed? Yes! At least from Gefen’s point of view they make the “fix” available as an add-on called the DVI Detective. From the consumer’s point of view I looked at what model from Gefen had this built-in and found this article that summed it up as big fat “NO”.

    I am hoping for further feedback on the gefen or addlogix KVM switches. What works? Anything?

  29. daizoe on December 20th, 2005 2:35 pm

    Any tip on what KVM i should go for if i need this:
    Got 2 computer
    one 20″ wide screen, res: 1650xsomething

    I found this one, but i cant find any reviews on it.

  30. Stux on March 23rd, 2006 10:39 pm

    “Any tip on what KVM i should go for”

    After using my Linkskey/Uniclass KVM for a LONG TIME now, and have ZERO issues to report.

    I’d heartily suggest one for a 20″ screen 🙂

    The Avocent SWITCHVIEW *looks* just like the Uniclass/Linkskey KVM and is probably simply the European rebadged version.

    As far as I can tell Uniclass makes them and markets them as Uniclass in Asia/Australia, They’re marketed and badged in North America by Linkskey as Linkskey, and they seem to be marketed/badged as SwitchView by Avocent in Europe.

    A fantastic DVI KVM, which is affordable, works with Apple Displays and Apple Equipment, and is even recommended by some Apple Engineers

  31. JB on May 27th, 2007 4:07 pm

    “Anyone else try the Avocent Switchview 4-port KVM switch (DVI)? Any success? I’m considering giving it a shot.”

    Skip this one entirely, if you want to save yourself from another problematic device. Yes, I had this unit for 27 days and lost the B1 port -it just went “dead” no response. Luckily I had 3 more ports left to use at the time. No joke, I tried everything in the book to get it working again, and the LED would not come on. There were some inherant lock-ups and I had to reset the power to the unit, often. I had high hopes for this unit and paid 299.00 plus shipping only to get a DUD. I bought it through which turned out to be another headache to get a FULL refund. Failed in 27 days out of a 30 day warranty allowing me to return it. I havn’t puchased a KVM since. Advocent wanted me to return the unit to them for repair, instead, I opted to refund the unit via retailer and be FREE of it.

    The dual boot OS method is my friend right now.

  32. Rod on August 20th, 2009 8:17 am

    Reading the manuals and specs provided by these companies, I think that the Uniclass DVI-202AU, Linkskey LDV-202AUSK, and the Avocent SwitchView DVI 2SVDVI10 are rebadged versions of some OEM manufacturer’s product. Unlike the others, Avocent actually has public updates available for this switch. I had nothing to lose except an extremely flakey switch (purchased 2nd hand, cheap, and USB switching was unuseable), so I flashed the Linkskey LDV-202AUSK with the firmware update 2SVDVI10_061129.uni from Avocent for their SwitchView DVI 2SVDVI10. It works (after a bit of worry that I had created yet another paperweight – had to power down everything including the computers) and so far it appears to be a useable DVI, USB, audio switch now.

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