Display issues with nouveau drivers

Hello,
I came back to Manjaro after a long while off and realized that my nvidia drivers 340.xx were no longer supported. My Manjaro installation reverted automatically to nouveau drivers for which I have display issues.

I get a lot artifacts/ghosting when scrolling in windows or when text blinks…

I managed to revert back to legacy nvidia 340.xx proprietary drivers with a how to from the forums which the fixed the display issue.

Anyone knows why the nouveau drivers are not working with my setup?
Is there an acceleration setting I could disable in gnome or wayland to make it work?

$ inxi -v7azy
System:
  Kernel: 5.10.194-1-MANJARO arch: x86_64 bits: 64 compiler: gcc v: 13.2.1
    clocksource: tsc available: hpet,acpi_pm
    parameters: BOOT_IMAGE=/vmlinuz-5.10-x86_64
    root=UUID=9d7922a1-6032-4a1e-95c3-aec8f235da3f rw quiet apparmor=1
    security=apparmor resume=UUID=996b53c4-a02d-4d60-a2d2-5b0480524ff5
    udev.log_priority=3
  Desktop: GNOME v: 44.4 tk: GTK v: 3.24.38 wm: gnome-shell dm: GDM v: 44.1
    Distro: Manjaro Linux base: Arch Linux
Machine:
  Type: Desktop System: ASUS product: All Series v: N/A
    serial: <superuser required>
  Mobo: ASUSTeK model: B85M-E v: Rev X.0x serial: <superuser required>
    BIOS: American Megatrends v: 3602 date: 04/04/2018
Battery:
  Message: No system battery data found. Is one present?
Memory:
  System RAM: total: 16 GiB available: 15.53 GiB used: 1.75 GiB (11.3%)
  RAM Report: permissions: Unable to run dmidecode. Root privileges required.
CPU:
  Info: model: Intel Core i7-4770 bits: 64 type: MT MCP arch: Haswell
    gen: core 4 level: v3 note: check built: 2013-15 process: Intel 22nm
    family: 6 model-id: 0x3C (60) stepping: 3 microcode: 0x28
  Topology: cpus: 1x cores: 4 tpc: 2 threads: 8 smt: enabled cache:
    L1: 256 KiB desc: d-4x32 KiB; i-4x32 KiB L2: 1024 KiB desc: 4x256 KiB
    L3: 8 MiB desc: 1x8 MiB
  Speed (MHz): avg: 3049 high: 3751 min/max: 800/3900 scaling:
    driver: intel_cpufreq governor: schedutil cores: 1: 3135 2: 2788 3: 3751
    4: 3358 5: 2980 6: 2684 7: 2906 8: 2795 bogomips: 54292
  Flags: abm acpi aes aperfmperf apic arat arch_perfmon avx avx2 bmi1 bmi2
    bts clflush cmov constant_tsc cpuid cpuid_fault cx16 cx8 de ds_cpl dtes64
    dtherm dts epb erms est f16c flush_l1d fma fpu fsgsbase fxsr ht ibpb ibrs
    ida invpcid invpcid_single lahf_lm lm mca mce md_clear mmx monitor movbe
    msr mtrr nonstop_tsc nopl nx pae pat pbe pcid pclmulqdq pdcm pdpe1gb pebs
    pge pln pni popcnt pse pse36 pti pts rdrand rdtscp rep_good sdbg sep smep
    smx ss ssbd sse sse2 sse4_1 sse4_2 ssse3 stibp syscall tm tm2 tsc
    tsc_adjust tsc_deadline_timer vme x2apic xsave xsaveopt xtopology xtpr
  Vulnerabilities:
  Type: gather_data_sampling status: Not affected
  Type: itlb_multihit status: KVM: VMX unsupported
  Type: l1tf mitigation: PTE Inversion
  Type: mds mitigation: Clear CPU buffers; SMT vulnerable
  Type: meltdown mitigation: PTI
  Type: mmio_stale_data status: Unknown: No mitigations
  Type: retbleed status: Not affected
  Type: spec_rstack_overflow status: Not affected
  Type: spec_store_bypass mitigation: Speculative Store Bypass disabled via
    prctl and seccomp
  Type: spectre_v1 mitigation: usercopy/swapgs barriers and __user pointer
    sanitization
  Type: spectre_v2 mitigation: Retpolines, IBPB: conditional, IBRS_FW,
    STIBP: conditional, RSB filling, PBRSB-eIBRS: Not affected
  Type: srbds mitigation: Microcode
  Type: tsx_async_abort status: Not affected
Graphics:
  Device-1: NVIDIA G92 [GeForce GTS 250] vendor: ZOTAC driver: nvidia
    v: 340.108 alternate: nouveau non-free: series: 340.xx status: legacy (EOL)
    last: release: 340.108 kernel: 5.4 xorg: 1.20 arch: Tesla process: 40-80nm
    built: 2006-13 pcie: gen: 2 speed: 5 GT/s lanes: 16 bus-ID: 01:00.0
    chip-ID: 10de:0615 class-ID: 0300
  Display: x11 server: X.org v: 1.21.1.8 with: Xwayland v: 23.2.0
    compositor: gnome-shell driver: X: loaded: nvidia gpu: nvidia display-ID: :1
    screens: 1
  Screen-1: 0 s-res: 1680x1050 s-size: <missing: xdpyinfo>
  Monitor-1: DVI-I-1 res: 1680x1050 hz: 60 dpi: 90
    size: 474x296mm (18.66x11.65") diag: 559mm (22") modes: N/A
  API: OpenGL v: 3.3.0 NVIDIA 340.108 renderer: GeForce GTS 250/PCIe/SSE2
    direct-render: Yes
Audio:
  Device-1: Intel 8 Series/C220 Series High Definition Audio vendor: ASUSTeK 8
    driver: snd_hda_intel v: kernel bus-ID: 00:1b.0 chip-ID: 8086:8c20
    class-ID: 0403
  API: ALSA v: k5.10.194-1-MANJARO status: kernel-api with: aoss
    type: oss-emulator tools: alsactl,alsamixer,amixer
  Server-1: sndiod v: N/A status: off tools: aucat,midicat,sndioctl
  Server-2: JACK v: 0.125.0 status: off tools: N/A
  Server-3: PipeWire v: 0.3.79 status: off with: pipewire-media-session
    status: active tools: pw-cli
  Server-4: PulseAudio v: 16.1 status: active with: 1: pulseaudio-alsa
    type: plugin 2: pulseaudio-jack type: module tools: pacat,pactl,pavucontrol
Network:
  Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet
    vendor: ASUSTeK P8 series driver: r8169 v: kernel pcie: gen: 1
    speed: 2.5 GT/s lanes: 1 port: d000 bus-ID: 03:00.0 chip-ID: 10ec:8168
    class-ID: 0200
  IF: enp3s0 state: down mac: <filter>
  Device-2: Qualcomm Atheros AR93xx Wireless Network Adapter driver: ath9k
    v: kernel pcie: gen: 1 speed: 2.5 GT/s lanes: 1 bus-ID: 04:00.0
    chip-ID: 168c:0030 class-ID: 0280
  IF: wlp4s0 state: up mac: <filter>
  IP v4: <filter> type: dynamic noprefixroute scope: global
    broadcast: <filter>
  IP v6: <filter> type: noprefixroute scope: link
  WAN IP: <filter>
Bluetooth:
  Message: No bluetooth data found.
Logical:
  Message: No logical block device data found.
RAID:
  Message: No RAID data found.
Drives:
  Local Storage: total: 465.76 GiB used: 46.56 GiB (10.0%)
  SMART Message: Required tool smartctl not installed. Check --recommends
  ID-1: /dev/sda maj-min: 8:0 vendor: Western Digital
    model: WD5000AAKS-00YGA0 size: 465.76 GiB block-size: physical: 512 B
    logical: 512 B speed: 1.5 Gb/s tech: N/A serial: <filter> fw-rev: 1C02
    scheme: GPT
  Optical-1: /dev/sr0 vendor: HL-DT-ST model: DVDRAM GH24NS95 rev: RN01
    dev-links: cdrom
  Features: speed: 12 multisession: yes audio: yes dvd: yes
    rw: cd-r,cd-rw,dvd-r,dvd-ram state: running
Partition:
  ID-1: / raw-size: 150 GiB size: 146.59 GiB (97.72%) used: 34.63 GiB (23.6%)
    fs: ext4 dev: /dev/sda5 maj-min: 8:5 label: N/A
    uuid: 9d7922a1-6032-4a1e-95c3-aec8f235da3f
  ID-2: /boot raw-size: 1024 MiB size: 973.4 MiB (95.06%)
    used: 143.5 MiB (14.7%) fs: ext4 dev: /dev/sda4 maj-min: 8:4 label: N/A
    uuid: 049fc73a-e301-4cf3-8773-3e28c8614855
  ID-3: /home raw-size: 306.5 GiB size: 300.62 GiB (98.08%)
    used: 11.78 GiB (3.9%) fs: ext4 dev: /dev/sda6 maj-min: 8:6 label: N/A
    uuid: 947ed60f-20e1-4ec3-b43b-390efdf59a13
Swap:
  Kernel: swappiness: 60 (default) cache-pressure: 100 (default) zswap: yes
    compressor: zstd max-pool: 20%
  ID-1: swap-1 type: partition size: 8 GiB used: 0 KiB (0.0%) priority: -2
    dev: /dev/sda3 maj-min: 8:3 label: N/A
    uuid: 996b53c4-a02d-4d60-a2d2-5b0480524ff5
Unmounted:
  ID-1: /dev/sda1 maj-min: 8:1 size: 8 MiB fs: <superuser required> label: N/A
    uuid: N/A
  ID-2: /dev/sda2 maj-min: 8:2 size: 250 MiB fs: vfat label: N/A
    uuid: 954E-4F53
USB:
  Hub-1: 1-0:1 info: full speed or root hub ports: 2 rev: 2.0
    speed: 480 Mb/s (57.2 MiB/s) lanes: 1 mode: 2.0 chip-ID: 1d6b:0002
    class-ID: 0900
  Hub-2: 1-1:2 info: Intel Integrated Rate Matching Hub ports: 6 rev: 2.0
    speed: 480 Mb/s (57.2 MiB/s) lanes: 1 mode: 2.0 chip-ID: 8087:8008
    class-ID: 0900
  Hub-3: 2-0:1 info: full speed or root hub ports: 2 rev: 2.0
    speed: 480 Mb/s (57.2 MiB/s) lanes: 1 mode: 2.0 chip-ID: 1d6b:0002
    class-ID: 0900
  Hub-4: 2-1:2 info: Intel Integrated Rate Matching Hub ports: 6 rev: 2.0
    speed: 480 Mb/s (57.2 MiB/s) lanes: 1 mode: 2.0 chip-ID: 8087:8000
    class-ID: 0900
  Hub-5: 3-0:1 info: hi-speed hub with single TT ports: 12 rev: 2.0
    speed: 480 Mb/s (57.2 MiB/s) lanes: 1 mode: 2.0 chip-ID: 1d6b:0002
    class-ID: 0900
  Device-1: 3-8:2 info: Microsoft Wireless Receiver 1461C
    type: keyboard,mouse,HID driver: hid-generic,usbhid interfaces: 3 rev: 2.0
    speed: 12 Mb/s (1.4 MiB/s) lanes: 1 mode: 1.1 power: 100mA
    chip-ID: 045e:07a5 class-ID: 0300
  Hub-6: 4-0:1 info: super-speed hub ports: 6 rev: 3.0
    speed: 5 Gb/s (596.0 MiB/s) lanes: 1 mode: 3.2 gen-1x1 chip-ID: 1d6b:0003
    class-ID: 0900
Sensors:
  System Temperatures: cpu: 34.0 C mobo: N/A gpu: nvidia temp: 47 C
  Fan Speeds (rpm): N/A gpu: nvidia fan: 25%
Info:
  Processes: 244 Uptime: 21m wakeups: 0 Init: systemd v: 253 default: graphical
  tool: systemctl Compilers: gcc: 13.2.1 clang: 16.0.6 Packages: pm: pacman
  pkgs: 1796 libs: 486 tools: gnome-software,pamac pm: flatpak pkgs: 0
  Shell: Bash v: 5.1.16 running-in: gnome-terminal inxi: 3.3.29

Most likely gpu performance issues. Nouveau cannot clock up the gpu thus it stays at the base clock, but you can adjust it manually in a experimental way for some older models.

The symptoms you mentioned are most likely a result of the base clock performance and that the Gnome Desktop needs 3D acceleration. The GPU cannot keep up thus it results in artifacts since it stuck at base clock for safety reasons.

Use another DE without any 3D acceleration or stick to a LTS Distro with a fixed release cycle.

You will not be very happy with such an old NVIDA card on Manjaro even if you managed the driver on Manjaro yourself.