We use Avocent KVMs they are pretty good but also a bit pricy.
My experience with KVMs is, you get what you pay for.

Boggles my mind that something so simple like a Y cable with a tiny switch doesn't exist for this purpose (two pc's to one monitor). I'm guessing I need something like a VGA amplifier to sustain quality (basically a hub), but I've only seen applications for multiple monitors and one PC (instead of one monitor and multiple vga sources).

EDIT:
This is the only decent looking vga selector I've come across: http://www.mcmelectronics.com/product/ACTIONS … -121A-/83-13355. It looks ugly. Why is it blue? It only has 400mhz bandwidth (why isn't there 550mhz?) ?... Is this like ramdac? Definitely need crisp display up to 2048x1536 (actually use higher resolutions interlaced).

I use the KVM for the PS/2 ports only. For the monitor I got a longer 3m VGA cable and just plug that into whatever device I need. Same goes for capturing.

Otherwise you just need to live with a loss in image quality. The other option is going with DVI / HDMI. You can do this on a Super Socket 7 board and higher and get excellent results.

I use Avocent, Belkin, and Startech KVMs myself and all work ok, but I may start doing what Mau1wurf1977 mentions above (suing the KVMs for PS/2 only) as there always seems to be some loss of quality of the VGA signal almost all the time. I also have some 15 pin VGA connector mechanical A-B switches I have used (the type with the large knob) and found them to work well, but I need the ability to switch between more than just two computers.

Thought a mechanical switch would simply pass-through the vga signal without degrading quality (especially with no wires or signal splitting involved). I'm using this one:

There's no wires inside, uses a PCB, and it degrades the signal as mentioned in my first post; no rubber feet either (bare metal). Really cheap and sturdy is the only thing good about it.

Ya, I have one of those as well and the quality is not very good...as I mentioned above (the one I refered to in my post above) is the one with the knob with wires inside.

You might find this interesting:

VGA signal quality - Splitters and KVMs

The KVM and the VGA splitter cause loss of signal. Using both degrades the image quite noticeably.

For capturing my best solution is using a GeForce FX in my Socket 7 machine. Play through VGA, capture through DVI. Zero issues.

If I capture from a 386, I will use the VGA splitter as playing through the AverMedia capture window is as much fun as a good day at work.

I have a strange setup where my S3 Virge wont display using my Compaq 8 port KVM but works when connected to a no name 4 port PS2 KVM I got of ebay around 2006. The Compaq has its own power source where the no name draws it from the host PC so I would think if anything it should work better on the Compaq?
Thing is if I connect the S3 to the 4 port and connect that to the Compaq it works! Don't know what the 4 port is doing different but I'm happy enough. My screen is a bashed around 15" TFT so not overly worried about signal quality anyway.

Holering wrote:

Thought a mechanical switch would simply pass-through the vga signal without degrading quality (especially with no wires or signal splitting involved).

There's no wires inside, uses a PCB, and it degrades the signal as mentioned in my first post; no rubber feet either (bare metal). Really cheap and sturdy is the only thing good about it.

The switch (and PCB too if it is poorly designed, including connectors) is a discontinuity in an otherwise uniform signal path (coaxial cable). Discontinuities in high speed signals cause reflections and reflections is what you see as blurry image. The switch may not be even meant for such high speed signals. It would be nice to see a photo of the PCB and switch inside, the copper traces on the PCB could form unwanted stubs in the signal path, and at certain signal frequencies the stubs act like short circuits.

Well I got this and it bloody sucks! The image looks sharp and doesn't soften, but I get this damn haze contrasted to bright edges (mouse pointer has haze over bright white backgrounds). This thing drives the signal to 450mhz too and I believe it had a demanding msrp. My rage128 with 250mhz ramdac looks way better (it actually looks practically the same as 8400 gs).

I'm pretty sure all of these switches will give you a loss in quality. So will VGA splitters, even powered ones. You could purchase a VGA to DVI / HDMI converter for every VGA output, but that's likely an expensive solution.

However, a lot of cards have DVI anyway. I use DVI in my Pentium machine and that runs all the DOS games. So you could just go all digital and avoid loss of signal quality.

I ended up using my KVM purely for the PS/2 ports. When capturing I connect the AVermedia directly to the source and use the recording image on the capture computer (it has really minimal lag and you can go full-screen), or I capture through DVI (I can either use a DVI 1 to 4 splitter) or a card that has dual outputs like most GeForce cards.

I had a setup once with 4 machines all ready to go and the signal going through a splitter, KVM. It was a very good setup in terms of everything being captured and no cables to be unplugged but the singal quality was suffering. I believe I took some screenshots in another thread and you can see how the image gets worse. I use good VGA cables as well.

So now I just use test benches and just put up with having to plug in cables more often but the image quality is a lot better. On a modern card like a GeForceFX I don't see a reason to go with VGA anymore. Especially at 1600 x 1200 resolution VGA simply reaches its limits.

keep meaning to ask Mau1wurf, Any plans on showing your fancy 20" off on Youtube? I keep thinking maybe about getting one but worried how blocky low res games like Doom look