Display issues still being a nuisance

A while back I purchased a nice fat Benq BL2710.

Besides the frustrating front panel buttons, it seems to be a really decent monitor, which I'd be really happy with if I could get Fedora Linux to drive it correctly.

Initially I was using the onboard Intel graphics, which simply refused to offer the resolution(s) I want to run at (2560 x 1440).

So I decided to try a seperate graphics card. After some reading that suggested it may be workable with Linux I went for a 4GB Gigabyte Radeon RX460.

[dafoot@bigfoot ~]$ lspci | grep VGA
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Baffin [Radeon RX 460] (rev cf)
[dafoot@bigfoot ~]$ 

Now under Fedora 25 there are included open drivers for this GPU and it appears my system has them installed:

[root@bigfoot ~]# lshw -c video
  *-display                 
       description: VGA compatible controller
       product: Baffin [Radeon RX 460]
       vendor: Advanced Micro Devices, Inc. [AMD/ATI]
       physical id: 0
       bus info: pci@0000:01:00.0
       version: cf
       width: 64 bits
       clock: 33MHz
       capabilities: pm pciexpress msi vga_controller bus_master cap_list rom
       configuration: driver=amdgpu latency=0
       resources: irq:131 memory:b0000000-bfffffff memory:c0000000-c01fffff ioport:e000(size=256) memory:de300000-de33ffff memory:c0000-dffff
[root@bigfoot ~]# 

So now my 'select resolution' interface at least recognised the Radeon 460 and the monitor as Benq BL2710.

So that's progress.

Unfortunately, any time I select that resolution, it is unusable....all fuzzy/jaggy.

Curiously, I just took a screenshot to add to this post while the scrren was a mess like that and the image showed all the text perfectly clearly.

I wonder if DisplayPort will behave any better if I try that.