144Hz monitor maxes out at 75Hz (DisplayPort)

Hardware GPU
,
1

My Hardware:

  • CPU: AMD Ryzen Threadripper 1950X
  • RAM: 2x16GB Crucial Ballistix Sport LT V2 DDR4-3200 (XMP 2.0 profile)
  • Mainboard: ASRock X399 Taichi
  • PSU: beQuiet Dark Power Pro 11
  • GPU: An old 8GB Sapphire Radeon RX 480 Nitro+ OC Active PCIe 3.0 x16 1xDVI / 2xDisplayPort / 2xHDMI 2.0 (Lite Retail). Sadly I don’t have any other GPU to see if it’s the GPU that causes the problem.

Monitors: LG UltraGear 38GN950-B ; Asus MG279Q ; an old 1080p TV

The Problem:
I can’t use my LG UltraGear 38GN950-B with anything higher than 75Hz. Windows doesn’t display the option. Manjaro does allow me to set the refresh rate to 144Hz, but then the monitor looses the signal and after some time it resets back 75Hz. When I turn on HDR, Windows tells me the monitor is using 75Hz while the monitor itself tells me it’s using 60Hz in HDR mode.

  1. LG UltraGear 38GN950-B Display Port
  2. Asus MG279Q Display Port to Mini Display Port (MiniDP for the monitor)
  3. 1080p TV: HDMI , currently turned off

What I’ve tried/checked so far:
The list might be a bit long as I’ve also asked a few people about this issue. Please note that I don’t really know what the log messages of dmesg try to tell me, thought those people I asked seem not to think that they are related:

  • The OSD menu of my monitor is set to use DP 1.4 (other options would be 1.1 and 1.2) and the resolution is set to 3480x1600p.
  • I use the monitor with the PSU that came with the monitor.
  • I checked it with the cable that came with the monitor and with the following cable
  • The AMD driver software under Windows tells me the monitor is connected via 5.4Gbps x4 via DP.
  • Setting the color depth from 10bit down to 8bit doesn’t change anything.
  • Turning off adaptive sync (under Windows) doesn’t change anything.

Everything below was tested with the following cable:
After trying out this command: # echo "4 0x1e" > /sys/kernel/debug/dri/0/DP-2/link_settings:

# cat /sys/kernel/debug/dri/0/DP-1/link_settings
Current:  4  0x14  0  Verified:  4  0x14  0  Reported:  4  0x14  16  Preferred:  0  0x0  0
# cat /sys/kernel/debug/dri/0/DP-2/link_settings
Current:  4  0x14  0  Verified:  4  0x1e  0  Reported:  4  0x1e  16  Preferred:  0  0x0  0

With the following dsmeg: dmesg-output.txt (130.8 KB)

Another try:

echo 0xf > /sys/module/drm/parameters/debug
reboot
echo "4 0x1e" > /sys/kernel/debug/dri/0/DP-2/link_settings

Results in this:

Output of dmesg.. only the relevant part after the commands above

Yep, ------------[ cut here ]------------ was part of the dmseg message.

[  164.423923] ------------[ cut here ]------------
[  164.423928] Buffer overflow detected (8 < 192)!
[  164.423939] WARNING: CPU: 27 PID: 2102 at include/linux/thread_info.h:199 ethtool_rxnfc_copy_to_user+0x2b/0xb0
[  164.423947] Modules linked in: rfcomm qrtr ns cmac algif_hash algif_skcipher af_alg bnep btusb snd_usb_audio btrtl btbcm snd_usbmidi_lib btintel snd_rawmidi snd_seq_device bluetooth mousedev joydev mc ecdh_generic ecc iwlmvm amdgpu intel_rapl_msr snd_hda_codec_realtek mac80211 snd_hda_codec_generic intel_rapl_common squashfs wmi_bmof mxm_wmi snd_hda_codec_ca0132 snd_hda_codec_hdmi ledtrig_audio libarc4 gpu_sched snd_hda_intel edac_mce_amd drm_ttm_helper snd_intel_dspcfg iwlwifi ttm snd_intel_sdw_acpi snd_hda_codec kvm_amd ext4 drm_kms_helper cfg80211 snd_hda_core kvm snd_hwdep snd_pcm crc16 mbcache vfat cec fat jbd2 snd_timer igb syscopyarea snd sysfillrect sp5100_tco sysimgblt irqbypass pcspkr fb_sys_fops k10temp i2c_piix4 soundcore rapl i2c_algo_bit rfkill dca wmi gpio_amdpt gpio_generic pinctrl_amd mac_hid acpi_cpufreq loop drm crypto_user fuse agpgart ip_tables x_tables btrfs blake2b_generic libcrc32c crc32c_generic xor raid6_pq usbhid dm_crypt cbc encrypted_keys dm_mod trusted
[  164.424026]  asn1_encoder tee tpm crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel crypto_simd cryptd ccp rng_core xhci_pci
[  164.424037] CPU: 27 PID: 2102 Comm: nmbd Tainted: G        W         5.13.19-2-MANJARO #1
[  164.424041] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./X399 Taichi, BIOS P3.60 02/19/2019
[  164.424042] RIP: 0010:ethtool_rxnfc_copy_to_user+0x2b/0xb0
[  164.424046] Code: 1f 44 00 00 41 55 65 48 8b 04 25 c0 7b 01 00 41 54 55 53 f6 40 10 02 75 23 be 08 00 00 00 48 c7 c7 20 7e 77 8f e8 aa 96 15 00 <0f> 0b 41 bc f2 ff ff ff 5b 44 89 e0 5d 41 5c 41 5d c3 48 89 fb 49
[  164.424048] RSP: 0018:ffff9e7a07e37bc0 EFLAGS: 00010282
[  164.424051] RAX: 0000000000000000 RBX: ffffffffc0ad8e60 RCX: 0000000000000027
[  164.424053] RDX: ffff892c5d4d8728 RSI: 0000000000000001 RDI: ffff892c5d4d8720
[  164.424054] RBP: ffff9e7a07e37bf0 R08: 0000000000000000 R09: ffff9e7a07e379f0
[  164.424056] R10: ffff9e7a07e379e8 R11: ffff892c7f2e53a8 R12: 0000000000000000
[  164.424057] R13: 00007fff91c4d360 R14: 0000000000000000 R15: ffff89252efa0000
[  164.424059] FS:  00007f34b3983540(0000) GS:ffff892c5d4c0000(0000) knlGS:0000000000000000
[  164.424061] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  164.424063] CR2: 0000560b0d9321e8 CR3: 0000000170732000 CR4: 00000000003506e0
[  164.424065] Call Trace:
[  164.424070]  ethtool_get_rxnfc+0xd3/0x1b0
[  164.424075]  dev_ethtool+0xc49/0x2d90
[  164.424078]  ? ____sys_recvmsg+0x104/0x1a0
[  164.424083]  ? inet_ioctl+0xe3/0x210
[  164.424087]  ? __mod_memcg_lruvec_state+0x22/0xe0
[  164.424092]  ? netdev_name_node_lookup_rcu+0x67/0x80
[  164.424096]  dev_ioctl+0x18d/0x4f0
[  164.424100]  sock_do_ioctl+0xee/0x190
[  164.424104]  sock_ioctl+0x278/0x360
[  164.424108]  __x64_sys_ioctl+0x82/0xb0
[  164.424113]  do_syscall_64+0x40/0x80
[  164.424118]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  164.424122] RIP: 0033:0x7f34b75b559b
[  164.424125] Code: ff ff ff 85 c0 79 9b 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a5 a8 0c 00 f7 d8 64 89 01 48
[  164.424127] RSP: 002b:00007fff91c4d2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[  164.424129] RAX: ffffffffffffffda RBX: 000000003b9aca00 RCX: 00007f34b75b559b
[  164.424131] RDX: 00007fff91c4d330 RSI: 0000000000008946 RDI: 0000000000000015
[  164.424132] RBP: 0000000000000015 R08: 0000000000000009 R09: 00007fff91c4d330
[  164.424133] R10: 0000000000000025 R11: 0000000000000246 R12: 0000000000000001
[  164.424134] R13: 000055967b553820 R14: 000055967b554ed8 R15: 000055967b554f7c
[  164.424138] ---[ end trace f8e438be82632056 ]---
[  164.424172] ------------[ cut here ]------------
[  164.424173] Buffer overflow detected (8 < 192)!
[  164.424180] WARNING: CPU: 27 PID: 2102 at include/linux/thread_info.h:199 ethtool_rxnfc_copy_to_user+0x2b/0xb0
[  164.424184] Modules linked in: rfcomm qrtr ns cmac algif_hash algif_skcipher af_alg bnep btusb snd_usb_audio btrtl btbcm snd_usbmidi_lib btintel snd_rawmidi snd_seq_device bluetooth mousedev joydev mc ecdh_generic ecc iwlmvm amdgpu intel_rapl_msr snd_hda_codec_realtek mac80211 snd_hda_codec_generic intel_rapl_common squashfs wmi_bmof mxm_wmi snd_hda_codec_ca0132 snd_hda_codec_hdmi ledtrig_audio libarc4 gpu_sched snd_hda_intel edac_mce_amd drm_ttm_helper snd_intel_dspcfg iwlwifi ttm snd_intel_sdw_acpi snd_hda_codec kvm_amd ext4 drm_kms_helper cfg80211 snd_hda_core kvm snd_hwdep snd_pcm crc16 mbcache vfat cec fat jbd2 snd_timer igb syscopyarea snd sysfillrect sp5100_tco sysimgblt irqbypass pcspkr fb_sys_fops k10temp i2c_piix4 soundcore rapl i2c_algo_bit rfkill dca wmi gpio_amdpt gpio_generic pinctrl_amd mac_hid acpi_cpufreq loop drm crypto_user fuse agpgart ip_tables x_tables btrfs blake2b_generic libcrc32c crc32c_generic xor raid6_pq usbhid dm_crypt cbc encrypted_keys dm_mod trusted
[  164.424241]  asn1_encoder tee tpm crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel crypto_simd cryptd ccp rng_core xhci_pci
[  164.424249] CPU: 27 PID: 2102 Comm: nmbd Tainted: G        W         5.13.19-2-MANJARO #1
[  164.424252] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./X399 Taichi, BIOS P3.60 02/19/2019
[  164.424253] RIP: 0010:ethtool_rxnfc_copy_to_user+0x2b/0xb0
[  164.424255] Code: 1f 44 00 00 41 55 65 48 8b 04 25 c0 7b 01 00 41 54 55 53 f6 40 10 02 75 23 be 08 00 00 00 48 c7 c7 20 7e 77 8f e8 aa 96 15 00 <0f> 0b 41 bc f2 ff ff ff 5b 44 89 e0 5d 41 5c 41 5d c3 48 89 fb 49
[  164.424257] RSP: 0018:ffff9e7a07e37bc0 EFLAGS: 00010282
[  164.424259] RAX: 0000000000000000 RBX: ffffffffc0ad8e60 RCX: 0000000000000027
[  164.424260] RDX: ffff892c5d4d8728 RSI: 0000000000000001 RDI: ffff892c5d4d8720
[  164.424262] RBP: ffff9e7a07e37bf0 R08: 0000000000000000 R09: ffff9e7a07e379f0
[  164.424263] R10: ffff9e7a07e379e8 R11: ffff892c7f2e53a8 R12: 0000000000000000
[  164.424264] R13: 00007fff91c4d360 R14: 0000000000000000 R15: ffff89252efa0000
[  164.424266] FS:  00007f34b3983540(0000) GS:ffff892c5d4c0000(0000) knlGS:0000000000000000
[  164.424267] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  164.424269] CR2: 0000560b0d9321e8 CR3: 0000000170732000 CR4: 00000000003506e0
[  164.424271] Call Trace:
[  164.424272]  ethtool_get_rxnfc+0xd3/0x1b0
[  164.424277]  dev_ethtool+0xc49/0x2d90
[  164.424280]  ? inet_ioctl+0xe3/0x210
[  164.424282]  ? __mod_memcg_lruvec_state+0x22/0xe0
[  164.424286]  ? netdev_name_node_lookup_rcu+0x67/0x80
[  164.424288]  dev_ioctl+0x18d/0x4f0
[  164.424292]  sock_do_ioctl+0xee/0x190
[  164.424296]  sock_ioctl+0x278/0x360
[  164.424299]  __x64_sys_ioctl+0x82/0xb0
[  164.424303]  do_syscall_64+0x40/0x80
[  164.424306]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  164.424308] RIP: 0033:0x7f34b75b559b
[  164.424310] Code: ff ff ff 85 c0 79 9b 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a5 a8 0c 00 f7 d8 64 89 01 48
[  164.424311] RSP: 002b:00007fff91c4d2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[  164.424314] RAX: ffffffffffffffda RBX: 000000003b9aca00 RCX: 00007f34b75b559b
[  164.424315] RDX: 00007fff91c4d330 RSI: 0000000000008946 RDI: 0000000000000015
[  164.424316] RBP: 0000000000000015 R08: 0000000000000009 R09: 00007fff91c4d330
[  164.424317] R10: 000000000000000d R11: 0000000000000246 R12: 0000000000000003
[  164.424319] R13: 000055967b553b80 R14: 000055967b555048 R15: 000055967b554d54
[  164.424321] ---[ end trace f8e438be82632057 ]---
[  164.424341] ------------[ cut here ]------------
[  164.424342] Buffer overflow detected (8 < 192)!
[  164.424349] WARNING: CPU: 27 PID: 2102 at include/linux/thread_info.h:199 ethtool_rxnfc_copy_to_user+0x2b/0xb0
[  164.424353] Modules linked in: rfcomm qrtr ns cmac algif_hash algif_skcipher af_alg bnep btusb snd_usb_audio btrtl btbcm snd_usbmidi_lib btintel snd_rawmidi snd_seq_device bluetooth mousedev joydev mc ecdh_generic ecc iwlmvm amdgpu intel_rapl_msr snd_hda_codec_realtek mac80211 snd_hda_codec_generic intel_rapl_common squashfs wmi_bmof mxm_wmi snd_hda_codec_ca0132 snd_hda_codec_hdmi ledtrig_audio libarc4 gpu_sched snd_hda_intel edac_mce_amd drm_ttm_helper snd_intel_dspcfg iwlwifi ttm snd_intel_sdw_acpi snd_hda_codec kvm_amd ext4 drm_kms_helper cfg80211 snd_hda_core kvm snd_hwdep snd_pcm crc16 mbcache vfat cec fat jbd2 snd_timer igb syscopyarea snd sysfillrect sp5100_tco sysimgblt irqbypass pcspkr fb_sys_fops k10temp i2c_piix4 soundcore rapl i2c_algo_bit rfkill dca wmi gpio_amdpt gpio_generic pinctrl_amd mac_hid acpi_cpufreq loop drm crypto_user fuse agpgart ip_tables x_tables btrfs blake2b_generic libcrc32c crc32c_generic xor raid6_pq usbhid dm_crypt cbc encrypted_keys dm_mod trusted
[  164.424409]  asn1_encoder tee tpm crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel crypto_simd cryptd ccp rng_core xhci_pci
[  164.424417] CPU: 27 PID: 2102 Comm: nmbd Tainted: G        W         5.13.19-2-MANJARO #1
[  164.424419] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./X399 Taichi, BIOS P3.60 02/19/2019
[  164.424420] RIP: 0010:ethtool_rxnfc_copy_to_user+0x2b/0xb0
[  164.424423] Code: 1f 44 00 00 41 55 65 48 8b 04 25 c0 7b 01 00 41 54 55 53 f6 40 10 02 75 23 be 08 00 00 00 48 c7 c7 20 7e 77 8f e8 aa 96 15 00 <0f> 0b 41 bc f2 ff ff ff 5b 44 89 e0 5d 41 5c 41 5d c3 48 89 fb 49
[  164.424424] RSP: 0018:ffff9e7a07e37bc0 EFLAGS: 00010282
[  164.424426] RAX: 0000000000000000 RBX: ffffffffc0ad8e60 RCX: 0000000000000027
[  164.424428] RDX: ffff892c5d4d8728 RSI: 0000000000000001 RDI: ffff892c5d4d8720
[  164.424429] RBP: ffff9e7a07e37bf0 R08: 0000000000000000 R09: ffff9e7a07e379f0
[  164.424430] R10: ffff9e7a07e379e8 R11: ffff892c7f2e53a8 R12: 0000000000000000
[  164.424431] R13: 00007fff91c4d360 R14: 0000000000000000 R15: ffff89252efa0000
[  164.424433] FS:  00007f34b3983540(0000) GS:ffff892c5d4c0000(0000) knlGS:0000000000000000
[  164.424434] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  164.424436] CR2: 0000560b0d9321e8 CR3: 0000000170732000 CR4: 00000000003506e0
[  164.424437] Call Trace:
[  164.424439]  ethtool_get_rxnfc+0xd3/0x1b0
[  164.424443]  dev_ethtool+0xc49/0x2d90
[  164.424446]  ? inet_ioctl+0xe3/0x210
[  164.424449]  ? __mod_memcg_lruvec_state+0x22/0xe0
[  164.424452]  ? netdev_name_node_lookup_rcu+0x67/0x80
[  164.424455]  dev_ioctl+0x18d/0x4f0
[  164.424458]  sock_do_ioctl+0xee/0x190
[  164.424462]  sock_ioctl+0x278/0x360
[  164.424465]  __x64_sys_ioctl+0x82/0xb0
[  164.424469]  do_syscall_64+0x40/0x80
[  164.424472]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  164.424474] RIP: 0033:0x7f34b75b559b
[  164.424476] Code: ff ff ff 85 c0 79 9b 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a5 a8 0c 00 f7 d8 64 89 01 48
[  164.424477] RSP: 002b:00007fff91c4d2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[  164.424479] RAX: ffffffffffffffda RBX: 000000003b9aca00 RCX: 00007f34b75b559b
[  164.424481] RDX: 00007fff91c4d330 RSI: 0000000000008946 RDI: 0000000000000015
[  164.424482] RBP: 0000000000000015 R08: 0000000000000009 R09: 00007fff91c4d330
[  164.424483] R10: 000000000000000d R11: 0000000000000246 R12: 0000000000000004
[  164.424484] R13: 000055967b553d30 R14: 000055967b555100 R15: 000055967b554d54
[  164.424487] ---[ end trace f8e438be82632058 ]---

Afterwards I tried to set it to 144Hz in the Manjaro settings menu (monitor lost signal, went back to 75Hz):

[  330.104350] [drm] DC global validation failure: Bandwidth validation failure (BW and Watermark) (13)
[  347.882456] usb 3-4.4: USB disconnect, device number 3
[  358.064760] usb 3-4.4: new full-speed USB device number 4 using xhci_hcd
[  358.155988] usb 3-4.4: New USB device found, idVendor=043e, idProduct=9a8a, bcdDevice= 5.21
[  358.155994] usb 3-4.4: New USB device strings: Mfr=1, Product=3, SerialNumber=4
[  358.155996] usb 3-4.4: Product: LG Monitor Controls
[  358.155998] usb 3-4.4: Manufacturer: LG Electronics Inc.
[  358.156000] usb 3-4.4: SerialNumber: [...]
[  358.315189] hid-generic 0003:043E:9A8A.0008: hiddev98,hidraw4: USB HID v1.11 Device [LG Electronics Inc. LG Monitor Controls] on usb-0000:08:00.3-4.4/input0
[  358.315947] hid-generic 0003:043E:9A8A.0009: hiddev99,hidraw5: USB HID v1.11 Device [LG Electronics Inc. LG Monitor Controls] on usb-0000:08:00.3-4.4/input1

And some images with additional information:

image
image1280×720 77.4 KB

image
image937×1294 99.8 KB

Setting a custom resolution doesn’t work:

image
image1081×699 62.5 KB

Setting the refresh rate to 144Hz and then changing the Timing Standard from “Manual” to “CVT - Reduced Blanking” means the G.Pixel Clock sets itself to “987250” which the AMD software doesn’t really like, thought I can save and apply that setting (which doesn’t resolve the problem).

2

Have u tried turning off, adaptive-sync? Then try re-enabling 144hz.

Doubt that Adaptive-sync even works above the 75hz range…

If you cant turn it off, try the settings on your monitor instead of software settings in the OS. Sometimes the monitor settings, inside the monitor can mess with actual settings in the OS.

3

Under Windows via the AMD driver. On Linux via the OSD menu of the monitor. In both cases, the problem remained.

Well, it’s AMD FreeSync Premium Pro. From what I’ve read, the range for this monitor is 48-144Hz for DP and 48-75Hz for HDMI.

4

Tried the OSD menu under windows? Its more likely to even respond to it than linux most likely.

Anyway you’ve been through ALL osd settings to make sure it’s not causing the issues?

Nice freesync range, would still turn it off when troubleshooting this kind of error.

Also not sure if i remember correctly, but freesync started with polaris didnt it? The RX 500 series of polaris anyway, so the gpu could but should not be the issue…

Are u using a single DP cable or dual? Some monitors require dual dp cables to run above 60hz at higher resolutions. Unsure if this applies to you or not, albeit worth a try :slight_smile:

5

Yes. At least I can’t see anything from the options below that could cause the problem.

Game Mode: sRGB
Game Adjust:

  • Overclock: off
  • Adaptive Sync / FreeSync / G-Sync compatible: on and off (tested with both)
  • Black Stabilizier: greyed out
  • Response Time: greyed out
  • Cross Hair: turned off

Picture Adjust:

  • Brightness: 30
  • Contrast: 70
  • Sharpness: greyed out
  • Gamma: greyed out
  • Color Temp: greyed out
  • R/G/B: greyed out
  • Six Color: greyed out
  • Black Level: greyed out
  • DFC: greyed out

Input:

  • Input: DisplayPort
  • Ratio: Full Wide
  • Auto Input Switch: On

General:

  • Waves Maxx Audio: On-ear
  • Language: English
  • Smart Energy Saving: Low
  • Lightning Option: Turn Off Lightning (when turning off the monitor)
  • Power LED: Off
  • Automatic Standby: 4h
  • HDMI Compatibility: greyed out
  • DisplayPort Version: 1.4
  • Local Dimming: Auto
  • Variable Backlight: greyed out
  • Buzzer: On
  • OSD Lock: Off

Just to make extra sure, the factory defaults don’t resolve the problem.

Just checked on Wikipedia: FreeSync started with the Radeon Rx 200 series ( GCN 2nd gen)

I’m using a single DP cable. The monitor has one DP and two HDMI connections.

6

About freesync, i meant actual mainstream support. Which came way later than RX 200 series, at that time it wasnt even named freesync, but adaptive-vsync. Whatever doesnt solve the issue here.

Well… There are some other options. There is a tool on windows called CRU utility, that enables custom refresh rates and resolutions. Which is definetly worth a try and could be cool too see what it comes up with on that monitor.

https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU

Before going the CRU utility route, is there perhaps an update for your monitor through LG support or something. Maybe a driver or monitor update/issue?

7

Ok. I just found something curious.

  • HBR3 (8.10 Gbit/s per lane)
  • HBR2 (5.40 Gbit/s per lane)

The AMD software tells me the monitor is using 5.40 Gbit/s x 4 which means the monitor is connected via HBR2. The question is, why is it not using HBR3 like it should use?

8

Not sure what HBR was in this matter. As it sounded like an encoder or something, like one of those the OBS software uses. VFR,HBR etc.

Anyway a search came up with displayport standards, would be cool if it had a list of supported video cards. As it seems that not all graphics cards offer the same support.

It could still be a myriad of things causing the issue and not everyone seems to be getting higher than 60hz on that specific monitor. Anyhow it does kind of sound like its being narrowed down to the rx 480, but to make sure. Research it before upgrading the card to/if something else.

TL:DR. Try to research the rx 480 card, to see if it supports the displayport configuration you’re using. In your case, if the card supports DP 1.3/4

9

Did you already try a different dp cable?

1 Like
10

That’s what I was going to suggest. Aside from club 3d which is what wendell suggested, there’s also this cable @zenstrata suggested in a recent thread

11

The RX480 supports DP 1.4.

Like stated in the original post: “I checked it with the cable that came with the monitor and with the following cable”

12

Ok, can still list some things that may be causing the problem…

Surely you’ve tried both first/second displayport output on the graphics card, yes?

Have u tried the other dp options in the OSD menu of the monitor? Like 1.1 and 1.2 just to see if it makes a difference or not.

Are u using the integrated usb-hub on the monitor? If yes, try disabling/removing or changing the USB cable. Otherwise for troubeshooting purposes, do not use the usb-hub at all.

Do u know any other people that have the same monitor without having the issue you’re having? If so you could ask for some information that way to see if for example the EDID code of the monitor matches yours.

The vbios output the amd software puts out has what looks like a pretty generic number. Maybe to generic (May be mistaken) But was the card bought used? If so it could have been replaced with a mining optimized vbios and windows could have problems replacing it the ‘normal way’ (With automatic driver install) if the card has a manually updated vbios.

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I’m not familiar with the seller. Can you confirm this is a genuine cable and not a knock-off? On Amazon, we have experienced a lot of non-genuine parts being sold in the US, so I am wondering if that happened to you.

Have you tried running it at 120hz? The DisplayPort 1.4 spec provides a total maximum data rate of 25.92Gbps, and 3840x1600@144 requires 26.54Gbps of bandwidth, at 8 bits per pixel. If you go to 10 bits per pixel, the requirement jumps to 31.85Gbps

I honestly don’t know how LG expects that display to be driven at 144hz, native resolution and HDR. Maybe DSC 1.2? I’m not that familiar with that feature though.

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There is software available for Windows that might be of help. There could also be a firmware update for the monitor. Read the Control Center manual to learn more.

Either way, it kinda looks like you are using HDMI or something as it maxes out at 10-bit 75Hz.

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Yeah, you would need a Turing GPU or Navi Gen 1 GPU to test that like the GTX 1660 or the RX 5500 XT. If the 1660 or 5500 XT hits 144hz, then it’s definitely a DP DSC 1.2 issue.

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OP was pretty clear about using DisplayPort.

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I tested that cable, too. Nope, no change.

I’ve tried using DP 1.2, but it does not change anything.

Already did that, no change.

Nope, the card was bought new.

I’ve checked the EAN and UPC-Codes on the package and they are the same as the one the website lists. There is also a QR code on the package that goes to the website. Not the best way to check it, but I don’t know of any other way. Thought I guess, when testing 3 DP 1.4 cables, one should do the job if it’s the cable.

Windows does not allow me to run the monitor at 120Hz. 75Hz is the max for non-HDR usage on Windows.

Nope, I’m using DP. Tested with the DP cable that came with the monitor, the club3D cable (EAN: 8719214470821, UPC: 841615101016)

That could take a while when looking at the current prices of any GPU.

Sadly I don’t know any other person using the same monitor. I know a friend of mine had problems with certan monitors and an RX 580, thought. Not sure what monitor it was, I only know that it was not the one I’m using.

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Have u tried any of the LG software? Which may include firmware updates to the monitor. Here’s a link to the windows 10 version

If the monitor reviews are correct on amazon, not everyone gets above 60hz on that monitor, perhaps hardware/firmware issues on specific models/shipments/batches.

LG should support RMA on those with those errors, but no idea if LG actually does that.

Otherwise, the CRU utility for windows could be useful to see if u can force the monitor in certain resolutions instead of having to still keep troubleshooting the monitor.

https://www.monitortests.com/forum/Thread-Custom-Resolution-Utility-CRU

If it’s not a software, OS, driver or cable issue. There is only firmware/hardware left. So updating the firmware somehow, either manually or through LG/other software may fix the bandwith problem (HBR3 connectivity)

Last but not least, maybe the monitor you’ve ordered has not been delivered with the advertised specifications or rather the support will be added at an later date. Which does actually happen in some cases. It could also mean, the monitor actually can’t work at advertised hz and resolution. Even though it says so on the box.

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Considering you do not have a DSC compatible GPU, you could try chroma subsampling, using YPbPr at 4:2:2 in limited range and 8 bit.

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As others are recommending, limiting display ranges could also work. That way it may some or much load of the bandwith and thereby display a prefferred resolution at an acceptable speed or in your case, what you’ve actually payed for.

That’s also why CRU utility was recommended, unfortunately i dont remember if it allows limiting / changing those kind of ranges. Still a nice utility for general usage or troubleshooting