- Xorg Server version: 1.20.3 - XRandR version: 1.5.0 - Xf86-Video-AMDGPU version: 18.0.1 - Kernel parameters: root=UUID=dfd3d587-145e-4c01-af04-a3e24c59e95c rw quiet rw rd.auto rd.auto=1 splash vfio-pci.ids=10de:1c03,1022:145f,1022:1457 modprobe.blacklist=nouveau iommu=pt amd_iommu=on kvm-amd.avic=1 kvm-amd.nested=1 clocksource=tsc kvm.ignore_msrs=1 pcie_acs_override=multifunction rd.driver.pre=vfio-pci video=efifb:off -------- Xorg.conf: Section "Device" Identifier "Device 0" Driver "amdgpu" VendorName "Advanced Micro Devices, Inc." BusID "PCI:34:0:0" Option "IgnoreEDID" "true" Option "UseEDID" "false" EndSection Section "Monitor" Identifier "Monitor 0" VendorName "SAMSUNG" ModelName "900SL" Option "UseEDID" "false" Option "UseEDIDFreqs" "false" Option "DDC" "false" HorizSync 30.0 - 96.0 VertRefresh 50.0 - 100.0 Modeline "1600x1200_76.00" 207.50 1600 1720 1888 2176 1200 1203 1207 1256 -hsync +vsync Option "PreferredMode" "1600x1200_76.00" EndSection -------- While connecting my XFX Radeon RX460 Slim to a Samsung 900SL CRT monitor via a DisplayPort to VGA converter cable, 1600x1200@76Hz is not available, despite the factory specs... 1600 x 1200 / 76 Hz 1600 x 1200 / 70 Hz 1600 x 1200 / 65 Hz 1280 x 1024 / 89 Hz 1024 x 768 / 119 Hz 800 x 600 / 152 Hz 640 x 480 / 160 Hz When attempting to create a new custom mode... mingcongbai@NetVista [ / ] $ cvt 1600 1200 76 # 1600x1200 75.92 Hz (CVT) hsync: 95.36 kHz; pclk: 207.50 MHz Modeline "1600x1200_76.00" 207.50 1600 1720 1888 2176 1200 1203 1207 1256 -hsync +vsync mingcongbai@NetVista [ / ] $ xrandr --newmode "1600x1200_76.00" 207.50 1600 1720 1888 2176 1200 1203 1207 1256 -hsync +vsync mingcongbai@NetVista [ / ] $ xrandr --addmode DisplayPort-0 "1600x1200_76.00" mingcongbai@NetVista [ / ] $ xrandr --output DisplayPort-0 --mode "1600x1200_76.00" xrandr: Configure crtc 0 failed I have an NVIDIA GeForce GTX1060 passed through to a Windows 10 VM, connected via a DisplayPort to VGA, and VGA to BNC 5-pin connector, in this case, 1600x1200 is available and displays a correct image. I have also tried to connect the RX460 with the DP-VGA-BNC cable, which yielded the same result.
I'm able to get the full 1600x1200@76Hz image with an active HDMI to VGA adapter. The image is a bit ghosted, but it's probably just the converter.
Created attachment 142766 [details] EDID Dump (from Xorg.0.log)
The EDID data (obtained from Xorg.0.log output and attached above) also suggests that such mode is possible (unless I misunderstood something). mingcongbai@NetVista [ / ] $ cat edid.bin | edid-decode EDID version: 1.2 Manufacturer: SAM Model 4db9 Serial Number 1346842937 Analog display, Input voltage level: 0.7/0.3 V Sync: Separate Composite SyncOnGreen Serration Maximum image size: 36 cm x 27 cm Gamma: 2.28 DPMS levels: Standby Suspend Off RGB color display First detailed timing is preferred timing Supports GTF timings within operating range Display x,y Chromaticity: Red: 0.6376, 0.3251 Green: 0.2763, 0.5957 Blue: 0.1425, 0.0664 White: 0.2832, 0.2978 Established timings supported: 720x400@70Hz 9:5 HorFreq: 31469 Hz Clock: 28.320 MHz 720x400@88Hz 9:5 HorFreq: 39500 Hz Clock: 35.500 MHz 640x480@60Hz 4:3 HorFreq: 31469 Hz Clock: 25.175 MHz 640x480@67Hz 4:3 HorFreq: 35000 Hz Clock: 30.240 MHz 640x480@72Hz 4:3 HorFreq: 37900 Hz Clock: 31.500 MHz 640x480@75Hz 4:3 HorFreq: 37500 Hz Clock: 31.500 MHz 800x600@56Hz 4:3 HorFreq: 35200 Hz Clock: 36.000 MHz 800x600@60Hz 4:3 HorFreq: 37900 Hz Clock: 40.000 MHz 800x600@72Hz 4:3 HorFreq: 48100 Hz Clock: 50.000 MHz 800x600@75Hz 4:3 HorFreq: 46900 Hz Clock: 49.500 MHz 832x624@75Hz 4:3 HorFreq: 49726 Hz Clock: 57.284 MHz 1280x768i@87Hz 5:3 HorFreq: 35522 Hz Clock: 44.900 MHz 1024x768@60Hz 4:3 HorFreq: 48400 Hz Clock: 65.000 MHz 1024x768@70Hz 4:3 HorFreq: 56500 Hz Clock: 75.000 MHz 1024x768@75Hz 4:3 HorFreq: 60000 Hz Clock: 78.750 MHz 1280x1024@75Hz 5:4 HorFreq: 80000 Hz Clock: 135.000 MHz 1152x870@75Hz 192:145 HorFreq: 67500 Hz Clock: 108.000 MHz Standard timings supported: 640x480@85Hz 4:3 HorFreq: 43300 Hz Clock: 36.000 MHz 800x600@85Hz 4:3 HorFreq: 53700 Hz Clock: 56.250 MHz 1024x768@85Hz 4:3 HorFreq: 68700 Hz Clock: 94.500 MHz 1280x1024@85Hz 5:4 HorFreq: 91100 Hz Clock: 157.500 MHz 1600x1200@75Hz 4:3 HorFreq: 93800 Hz Clock: 202.500 MHz 1024x768@100Hz 4:3 Detailed mode: Clock 157.500 MHz, 352 mm x 264 mm 1280 1344 1504 1728 hborder 0 1024 1025 1028 1072 vborder 0 +hsync +vsync VertFreq: 85 Hz, HorFreq: 91145 Hz Monitor ranges (GTF): 50-160Hz V, 30-96kHz H, max dotclock 210MHz Monitor name: S/M 900SL Serial number: H3NN105750 Checksum: 0xe0 (valid)
Using the same cable, the NVIDIA GeForce GTX1060 using proprietary driver version 410.66 is able to drive 1600x1200@76Hz with no issue.
Created attachment 142767 [details] Kernel Configuration - 4.19.0
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