[Bug] MangoHub high CPU usage with VRR on
Author: dmzkrskCreated Aug 22, 2026Updated Sep 8, 2026
Labelsbug
Describe the bug
High CPU usage on mangoapp process after latest Bazzite update
Linux distribution
Bazzite
MangoHud version
mangohud-0.8.4-1.fc44
Version check
- I have tested and can reproduce this on latest git.
GPU
AMD Radeon RX 9060 XT
GPU driver
Mesa 26.2.1
MangoHud installation method
Shipped with Bazzite
Application installation method
Pre-installed
Steps to reproduce
Update to latest bazzite version (21 aug 2026)
Turn on PC
High CPU usage right after boot with perfomance overlay enabled in Steam, even not shown
Check via htop or something
Disabling VRR in perfomance side menu drops CPU usage to 2.5% immediatly
Expected behavior
Regular CPU usage
Logs and terminal output
`perf` result in good mode:
Samples: 178 of event 'cpu/cycles/P', Event count (approx.): 1063318490
Children Self Command Shared Object Symbol
+ 65.72% 0.00% mangohud-amdgpu libc.so.6 [.] __GI___clone3
+ 65.72% 0.00% mangohud-amdgpu mangoapp [.] execute_native_thread_routine
+ 65.72% 0.00% mangohud-amdgpu mangoapp [.] AMDGPU::metrics_polling_thread()
+ 65.72% 1.65% mangohud-amdgpu [kernel.kallsyms] [.] entry_SYSCALL_64_after_hwframe
+ 64.07% 0.00% mangohud-amdgpu libc.so.6 [.] __syscall_cancel_arch_end
+ 64.07% 1.49% mangohud-amdgpu [kernel.kallsyms] [.] do_syscall_64
+ 58.92% 0.00% mangohud-amdgpu libc.so.6 [.] __syscall_cancel
+ 58.92% 0.00% mangohud-amdgpu mangoapp [.] AMDGPU::get_instant_metrics(amdgpu_common_metrics*)
+ 58.91% 0.00% mangohud-amdgpu libc.so.6 [.] _IO_file_underflow@@GLIBC_2.2.5
+ 58.91% 0.00% mangohud-amdgpu libc.so.6 [.] read
+ 58.91% 0.00% mangohud-amdgpu [kernel.kallsyms] [.] ksys_read
+ 58.91% 0.00% mangohud-amdgpu [kernel.kallsyms] [.] vfs_read
+ 58.91% 0.00% mangohud-amdgpu [kernel.kallsyms] [.] seq_read_iter
+ 58.91% 0.00% mangohud-amdgpu [kernel.kallsyms] [.] sysfs_kf_seq_show
+ 58.91% 0.00% mangohud-amdgpu [kernel.kallsyms] [.] dev_attr_show
+ 58.91% 0.00% mangohud-amdgpu [kernel.kallsyms] [.] smu_cmn_get_metrics_table
+ 58.91% 0.00% mangohud-amdgpu [kernel.kallsyms] [.] smu_cmn_update_table_read_arg
+ 58.91% 0.00% mangohud-amdgpu [kernel.kallsyms] [.] smu_cmn_send_smc_msg_with_params_ext
+ 58.91% 0.00% mangohud-amdgpu [kernel.kallsyms] [.] smu_msg_v1_send_msg
+ 58.91% 0.00% mangohud-amdgpu libc.so.6 [.] _IO_fread
`perf` result in bad mode:
Samples: 1K of event 'cpu/cycles/P', Event count (approx.): 66187893493
Children Self Command Shared Object Symbol
+ 93.06% 0.00% mangoapp mangoapp [.] _start
+ 93.06% 0.00% mangoapp libc.so.6 [.] __libc_start_main@@GLIBC_2.34
+ 93.06% 0.00% mangoapp libc.so.6 [.] __libc_start_call_main
+ 93.06% 0.00% mangoapp mangoapp [.] main
+ 83.04% 0.15% mangoapp mangoapp [.] render(GLFWwindow*, overlay_params&)
+ 66.59% 0.91% mangoapp libX11.so.6.4.0 [.] _XReply
+ 65.21% 2.25% mangoapp [kernel.kallsyms] [.] do_syscall_64
+ 64.27% 0.06% mangoapp [kernel.kallsyms] [.] entry_SYSCALL_64_after_hwframe
+ 63.37% 0.41% mangoapp libc.so.6 [.] __syscall_cancel_arch_end
+ 62.99% 0.20% mangoapp libc.so.6 [.] __syscall_cancel
+ 56.11% 0.50% mangoapp libxcb.so.1.1.0 [.] _xcb_conn_wait.part.0
+ 38.89% 0.00% mangoapp mangoapp [.] ImGui_ImplGlfw_NewFrame()
+ 36.96% 0.13% mangoapp libX11.so.6.4.0 [.] XGetWindowAttributes
+ 36.51% 0.10% mangoapp libX11.so.6.4.0 [.] _XGetWindowAttributes
+ 34.07% 0.00% mangoapp libxcb.so.1.1.0 [.] xcb_wait_for_reply64
+ 31.92% 0.56% mangoapp libxcb.so.1.1.0 [.] wait_for_reply
+ 25.58% 0.00% mangoapp libxcb.so.1.1.0 [.] xcb_writev
+ 25.58% 0.29% mangoapp libX11.so.6.4.0 [.] _XSend
+ 25.33% 0.00% mangoapp libglfw.so.3.4 [.] _glfwGetWindowSizeX11
+ 25.02% 0.20% mangoapp libxcb.so.1.1.0 [.] _xcb_out_sendScreenshots
No response
Additional context
- mangohud-0.8.4-1.fc44
- kernel 7.2.0-ogc4.1.fc44
- AMD Radeon RX 9060 XT
- 3840×2160 at 144 Hz
- using DisplayPort
- VRR, HDR enabled
There's also warning about unknown nis_steam_sharpness param
Source: flightlessmango/MangoHud