KVM switch + Windows 7 creates monitor switching nightmare

ATI Radeon 3100 Graphics through a Belkin Flip DVI to a Acer P241W

I'm running VMware workstation 6.5 and if I leave it running full screen when I switch back it will  occupy a fraction of the screen. After a few times the background will disappear and eventually Windows 7 will become unresponsive even though VMware continues to work fine.  I also see the same behavior when I switch the monitor off but leave the KVM switch to Win7.

Hardware is an AMD Phenom Quad core with 8Gb memory running Win7 Pro x64

I'd been running the same config for months with RC and then  FCS over a VGA KVM without problems.

I do have solutions for all the issues listed regarding video problems with KVM switch connected/switched to Windows 7 systems.

Please refer to following link (http://en.wikipedia.org/wiki/KVM_switch#Compatibility ) which does answer what caused the video problems – the KVM switches did not pass EDID data via DDC channel to Windows 7 continuously.   Disconnect or power on/off, or switching display devices from Windows 7 will trigger HPD (Hot Plug Detect) events to Windows 7.  Feeding Windows 7 with EDID data all the time can solve this kind of problems easily.  There are two ways to do it.

1)   If you want to keep your old KVM which can not feed EDID to Windows 7 systems, just adding a DDC/EDID emulator in between your KVM switch and each connected Windows 7.   The street price of VGA DDC/EDID emulator is about US$35~55/each.   It’s about $45~75 for DVI version.

2)   If you have too many of Windows 7 systems connected to the old KVM switch, it is simply too costly to add more than 3 DDC/EDID emulators to one old KVM switch.  Replacing the old KVM switch is suggestion.  Do your own calculation.  ($40x 3 = $130 which is the average marketing price for 4-port KVM switch with the all-time DDC/EDID feeding function).

Of cause, different  DDC/EDID emulators have different quality.  You can google it by using “DDC Ghost” “EDID Emulator” “DDC EDID Emulator” for the right emulator for your target.

Or you can google it by using “All-time DDC KVM” “Full DDC KVM” for those KVM switches support DDC emulation to all connected systems.

Since, so many KVM users having these same video issues with Windows 7,

I think the KVM makers will response to this demand to release more KVM switch models support the “All-time Full DDC/EDID” soon.

Thanks for the information everyone, please continue to post your KVM Make/Model as well as graphics card as the information is very helpful.

Thanks,

Kevin

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TrendNet TK-803R USB 8 port KVM

Here are some notes from my original post:

You know - I reported this problem in the beta stage of Win7 - and was told that it had to be something with the drivers - or the fact that I had a 'Cheap' KVM.

I'm glad to see that it's not just me and my $250 'Cheap' 8 port KVM switch.  I have this problem on any machine (with different Video Cards) where I install Windows 7.

It's even worse on my Primary Workstation with a NVidia GEForce 7900 GS.  I couldn't install Windows 7 on this machine if it was connected through the KVM.  As soon as it get's to the Windows Environment - the screen goes blank and never shows up.  I have to unplug the video from the KVM - plug it directly into the monitor - setup the system - and then install the Last Pre-Windows 7 Vista driver before I can switch back to my KVM.  That's just ridiculous...

Other notable side-affects:

     Every time I install a program - my Icon's re-sort back to auto-arrange (and no - it's not set to auto-arrange)

     If I'm on another system - I will periodically hear the 'Device Detached' or 'Device attached' sound.  Most times that's all that will happen - but occasionally it will lower my resolution from 1920x1200 to 1600x1200

     If I reboot the system while on another system - it defaults to the 1600x1200 resolution.

Obviously they don't appear to use KVM's in the development groups...

Joseph W. Leathlean

Same problem here. If the monitor is off when the OS boots, it reverts to the pathetic default 800x600 resolution messing up all my desktop icons. Nice *FEATURE* MS...Now how about a hack to disable it?