This problem is fixed in the Catalyst 10.4 Preview driver [update: and Cat 10.4 WHQL].
But i now have a LCD panel (Dell U2410) attached (via DVI-D) to my HD5870 system, that's another way to solve the problem.
Btw, i now finally see for myself that display-quality can be much better than what i was used to. And it feels better to the eyes too. I'd happily throw all my CRT's out'thewindow!
My other PC's are still with CRT but they have HD4xxx and 3xxx cards (for how long though...?).
Main PC: Asus TUF Gaming 570-Pro (wi-fi) * AMD Ryzen 7 5800X * Noctua NH-D15 * Corsair Vengeance LPX 32GB * Asus TUF Radeon 6800XT * Creative AE-9PE * 2 x Samsung 980 Pro * 7 x WD Gold HDD * Corsair HX 1000 * 1 x Asus DRW-24D5MT * Dell U3010 * Windows 10 x64 *
Office PC: Asus ROG Strix X570-E * AMD Ryzen 7 3800X * Noctua NH-D15 * Corsair Vengeance LPX 32GB * MSI Radeon 5700XT * Creative Soundblaster ZxR * 2 x Corsair Force MP600 * 7 x WD Gold HDD * Corsair AX 1200W * 1 x Asus DRW-24D5MT * Dell P4317Q * Windows 10 x64 *
Old workhorse PC: * Intel i7 4790K * Noctua NH-D15S * Asus Maximus VII Hero * Corsair Force MP510 480GB M.2 SSD * 32 GB Corsair Dominator Platinum CMD32GX3M4A2133C9 * Sapphire Radeon R9 290 * 3 x Dell U2410 @ Eyefinity 5760 x 1200 * Corsair HX 1000i * 7 x WD Black / Gold HDDs * Creative Soundblaster ZxR * Asus DRW F1ST * Corsair K95 RGB * Corsair M65 PRO RGB * Steelseries 9HD * Coolermaster STC T01 * Edifier S530 * Sennheiser HD598 * Windows 10 x64 *
Eek I recently saw some budget 'full HD' 1920x1080 monitors having only VGA (D-Sub) connection! I didn't know they even existed like that (i thought all LCD's at least use DVI-D).
So those were affected by this bug as well... Hopefully it never returns.
Main PC: Asus TUF Gaming 570-Pro (wi-fi) * AMD Ryzen 7 5800X * Noctua NH-D15 * Corsair Vengeance LPX 32GB * Asus TUF Radeon 6800XT * Creative AE-9PE * 2 x Samsung 980 Pro * 7 x WD Gold HDD * Corsair HX 1000 * 1 x Asus DRW-24D5MT * Dell U3010 * Windows 10 x64 *
Office PC: Asus ROG Strix X570-E * AMD Ryzen 7 3800X * Noctua NH-D15 * Corsair Vengeance LPX 32GB * MSI Radeon 5700XT * Creative Soundblaster ZxR * 2 x Corsair Force MP600 * 7 x WD Gold HDD * Corsair AX 1200W * 1 x Asus DRW-24D5MT * Dell P4317Q * Windows 10 x64 *
Old workhorse PC: * Intel i7 4790K * Noctua NH-D15S * Asus Maximus VII Hero * Corsair Force MP510 480GB M.2 SSD * 32 GB Corsair Dominator Platinum CMD32GX3M4A2133C9 * Sapphire Radeon R9 290 * 3 x Dell U2410 @ Eyefinity 5760 x 1200 * Corsair HX 1000i * 7 x WD Black / Gold HDDs * Creative Soundblaster ZxR * Asus DRW F1ST * Corsair K95 RGB * Corsair M65 PRO RGB * Steelseries 9HD * Coolermaster STC T01 * Edifier S530 * Sennheiser HD598 * Windows 10 x64 *
I recently saw some budget 'full HD' 1920x1080 monitors having only VGA (D-Sub) connection! I didn't know they even existed like that (i thought all LCD's at least use DVI-D).