I need a Mac/Monitor/keyboard switcher for DisplayPort Monitor

iogear.com has a "mDP" and "DP" category under "KVM products"

https://www.iogear.com/solutions/kvm/?filters=18|138

 

Stay far far away from Startech when dealing with mac.

I made that mistake previously.

 

In my experience, it's more reliable to plug the computers into separate video inputs on the monitor, and use a plain USB switch (as dumb as possible) for the K/M.

 

Easiest way to eliminate everything but the 2nd Mac Pro's video card is to directly connect the 2nd Mac Pro to your monitor via DisplayPort (eliminate the KVM) with the Mac turned off. Then boot up. Do you still get a black screen? If so then the KVM is not the problem. You mentioned you couldn't get a picture with direct connection but not sure if you tried that by hotplugging or with the power off.

If you get a black screen even with a direct connection, try clearing the NVRAM (easiest to use a wired keyboard for that if you have one). If you don't know how to do that just google Mac clear NVRAM.

You never mentioned what video cards you are using in the two machines. Are they the stock cards or something aftermarket? What resolution(s) are you running? You could try swapping the video cards on the two Mac Pros. Does the problem then move to Mac Pro #1? Then the problem is the video card. If it stays on Mac Pro #2 then perhaps it's a driver or OS issue.

 

Edit: Read the last paragraph first!

Sounds like you're using the stock cards. The GT120 was stock for the 2009 and the 5770 was stock for the 2010.

Yep, PRAM/NVRAM procedure is exactly the same. It's definitely worth a try to clear it on the system you're getting a black screen on since some display parameters are stored there.

You should also try using the mini-displayport->displayport adapter and displayport cable from Mac #1 just to rule out an issue with the ones you're using on Mac #2.

Not sure if you are comfortable opening up the two machines to swap video cards but I would try that too.

One other thing in general with a KVM is that the order you connect the cables to the KVM can be important. The KVM has to communicate with the monitor to find out the monitor's native resolution, which the KVM then must communicate to the attached computers. It may be a good idea to connect all the cables to the KVM, power on the monitor, then power on the KVM, then power on each of the computers.

Actually, now that I'm re-reading your original post, here's another suggestion. You can easily adapt HDMI to DVI in either direction (adapters are dirt cheap and very reliable). So you could adapt your new monitor's HDMI port to DVI and just use your old DVI KVM. In my experience DisplayPort is a really finicky, temperamental standard. It's sort of unavoidable right now for people doing 4K resolution, although even that is changing with HDMI 2.0.

Hope something there helps you.

 

Like I said before, if your new monitor has HDMI and you already have a perfectly-working DVI KVM switch then just buy a simple HDMI->DVI adapter and return the DisplayPort KVM. IMHO DisplayPort is a really crappy standard fraught with all kinds of instability and incompatibility. Since you don't appear to be using 4K I really think the simplest (and cheapest) course of action is just to adapt your monitor's HDMI port to DVI and call it a day.

You can get something like this: https://www.amazon.com/AmazonBasics-Input-Output-Adapter-Cable/dp/B014I8UQJY which has HDMI on one end (for the monitor side) and DVI on the other end to plug into your KVM's output.

If the KVM's output cable is captive (permanently attached) then you can get something like this: https://www.amazon.com/StarTech-com-DVI-D-Video-Cable-Adapter/dp/B009YCASUW which has a female DVI connector to plug your KVM's output cable into and an HDMI male connector to plug into your monitor.

DVI and HDMI actually use the same exact video signals, just in different connectors. So HDMI-DVI adapters are very cheap and very reliable.

 

OK. Well at least you've got options going forward. If you decide to stick with the DisplayPort KVM and get it fully working, please post back here so other Mac users who may find this thread in the future will know if it works with Macs or not.

 

If it works after you swap them back then you may not have connected everything in the right order the first time. Again, start with everything turned off. Connect the KVM output to your monitor, then connect both Macs to the KVM's inputs. Then power on in this order:

1. Monitor
2. KVM
3. Macs

That should allow the KVM to read the EDID info from the monitor, which it will then repeat to the Macs once they are powered on.

 

https://www.youtube.com/user/Ligawo/videos

Maybe they don't have KVM videos there.

 

Weird, but not altogether surprising because DisplayPort sucks, lol. Well you know what my advice is so I'll refrain from spouting it again. Good luck whatever you end up doing.

 

I never heard that one, but HDMI does suck (as well as Thunderbolt for display purposes).