KVM switches

Anybody used/using one of these?

I'm considering getting one as I already have a dual monitor setup, and need a test PC alongside my dev system but I don't want, or have space for, another monitor, mouse and keyboard on my desk.

1. Which KVM switch would you recommend?
2. Is there any mouse/keyboard lag?
3. Do they reduce the monitor signal to crap?
4. Any specific feature/spec I should look for?
5. Anything I should avoid?
6. How will it all plug into and affect an existing dual monitor setup?

Both my mouse and keyboard are standard USB ones. I do have PS2 ports on both PCs but I'd rather keep it all USB if possible.

Ta!

In my experience of KVM switchs they dont affect it at all, this was back when they only had PS/2 ports on. The one we had a work was a 5xinput(Video, PS2 keyboard and mouse) and 1x Output). That worked like a dream TBH :)

Would recommend them entirely

Yep got a 4 port KVM and they are a god send if you have two or more machines and hardly any space.

In answer to your questions

1. Which KVM switch would you recommend?
That depend on what you are willing to pay but take note you will also have to buy the leads to go with it as they are a separate item.

2. Is there any mouse/keyboard lag?
Never notice any.

3. Do they reduce the monitor signal to crap?
Yet again I never noticed any.

4. Any specific feature/spec I should look for?
Yes make sure that you buy one with audio support. And dual monitor support (this could narrow your choice of KVM's)

5. Anything I should avoid?
Make sure that the switching process use a key combination that is never use e.g press ctrl+scroll lock twice (the one I have use three taps of the ctrl key in quick succession which is a b*tch if you are playing a game)

6. How will it all plug into and affect an existing dual monitor setup?
This one I wouldn't really be able to answer as I will be looking into this my self sometime in the near future. Though I am looking at a Belkin Omniview Soho Series line of KVM's)

a year or so ago i set my dads two computers up with this one
http://catalog.belkin.com/IWCatSectionView.process?Section_Id=206974

it works great, just press a button to switch between the two computers.
theres a very small amount of lag during the switch but then its fine.

as for dual monitor set up i can't answer that.

That depends on a couple of factors... PS/2 vs. USB, VGA vs. DVI, single screen vs. dual screen, etc...



Not that I've ever noticed -- but there is a bit of a catch: Many of the KVM's have hotkeys that can't be disabled, which *can* interfere with certain programs/games. Depending on the make/model pressing Scroll Lock twice may have special meaning (e.g. switch to the next monitor, or in case of >2 heads you may type additional info such as the number of the PC you wish to connect to, or Left/Right cursors to walk through the list)
ScrollLock may be innocent since it's rarely used twice in a row, but others use CTRL. Hitting CTRL twice is pretty common if your playing games with a keyboard, so those could cause issues... (Especially since you typically can't disable the shortcuts: the KVM simply intercepts them in its own hardware)

At my work computer I love being able to switch by using CTRL-CTRL (convenient place on the keyboard), but at home it would be completely unworkable because it would break every other game.



There is a definite degradation of the VGA signal in the ones I've used over the years (several different brands/models. E.g. a slightly ghosted double-vision slightly to the right of images, and/or a visibly moving refresh bar slowly going from the top to the bottom of the screen... It's still usable, but seeing the KVM and non-KVM version side-by-side it's not difficult to pick which is which.
However: A big reason for that is that VGA cables normally aren't recommend to exceed 6 feet, and in a typical KVM setup you end up with twelve feet in cables plus the box itself. You may get a sharper image by intentionally getting some short(er) VGA cables instead of the standard 6 footers.

If you have DVI, then there are DVI-based KVM's. Unfortunately those are much more expensive, and last time I was looking around for one and read a bunch of reviews, they all seem to be crap on top of that. (e.g. intermittend problems passing through a signal requiring a powercycle, etc.). In theory the DVI ones would be much nicer since you don't have the crappy analog signal getting deformed through the whole setup, but unfortunately it seems that DVI KVM's are still in their infancy.



- Make sure it has the ports you need (USB vs. PS/2)
- Make sure that any built-in hotkeys it supports won't interfere with your normal work (or gaming). You can probably find this out by downloading the user manual from the manufacturer's website, and looking up what they are.
- Some of the KVM's come with attached cables, which will likely be cheaper, but also means that you can't change them for shorter ones (which would degrade the VGA signal less)



See my other points above and below...



None of the KVM's I've used have been dual monitor aware. If you are intending to switch two screens, you either need to:

1) Get a KVM that specifically supports dual screen
2) Use two single-screen KVM's (which would be inconvenient, especially since you wouldn't be able to use a keyboard hotkey to switch the second screen)

I should add, I'm not bothered about having both screens on both PCs. I just want to be able to switch one over (I don't care if the other one goes off when I do that).

The possibility of ghosting means I probably won't bother going down this route unless I can identify specific brands that don't suffer this problem.

If you only hook up one screen to the KVM, then the other won't be affected at all -- it will continue to show the same desktop screen, since it'll be connected straight to it.

Make sure to check the maximum supported resolution, some of them can't go higher than 1024x768.

I noticed a degrade in video quality as well with the two kvm switches i've owned. It wasn't too bad on a CRT monitor, but on LCD.. I just got rid of the switch, it was that bad. So it all depends on the quality of the product I guress.

input director. Or synergy if you like more bugs and cross platform support

Thanks for that. Running Input Director now and its awesome!

Its especially good since I just found out that half of the keys on my spare keyboard don't actually work anyway. :)

I got an IOGEAR 4-Port USB KVM switch(Model GCS634U) and have been very happy with it. I use it to control 2 pcs and 2 macs. The video does have a little quality loss but it's acceptable.

The cool thing about this model is that it fits under my monitor base(very small), comes with two cables attached and two extras (so you can just use 2 if you are only switching 2 boxes), and is all keyboard controlled. Another nice feature is that you can play music from one machine while using the rest of the KVM on another machine.

I've also had a Belkin SOHO in the past and had nothing but problems with it.