I have a computer running an AMD FirePro w600 with six 24" monitors.
It's been working great for about 4 years.
A couple days ago the hard drive died, so I replaced it.
I installed the latest version of Win10 Pro.
I didn't have to load any drivers for the w600.
I set it up and everything worked. All the monitors fired up and I only needed to adjust the order of the monitors to match.
The next day, one of the monitors is running at 25% the resolution of the rest of the monitors.(which are at 1920x1200).
When I try to change the resolution, the resolution choices are grayed out.
I double checked the connections. No luck.
I download the latest AMD driver. No luck.
What happened between yesterday and today, and how can I fix it?
what Multi-screen software are you using? AMD Eyefinity or Windows or some other software?
How are all 6 Monitors connected?
Have you to tried using another monitor and cable on the same GPU video output that has the wrong resolution to see if it is a GPU or Driver issue or possibly a cable or Monitor issue.
To eliminate a failing cable or monitor use one that you know is working correctly and see if there are any changes.
Here is the latest AMD Driver for your FirePro W600 : https://www.amd.com/en/support/professional-graphics/firepro/firepro-wx000-series/firepro-w600
All 6 monitors are HDMI and are attached with Eyefinity compatible active mini-DP to HDMI adapters.
I tried the Windows driver 1st, which worked for 1 day, then today tried the driver at the link you provided.
Again, everything has worked great for 4 years until a couple days ago when the hard drive on the systems needed replaced. It worked for 1 day and today is not.
I haven't tried another cable, but have checked connections.
could your miniDP>HDMI adapter be defective?
I know adapters can output lower resolutions if it isn't the correct adapter or it is going bad.