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Codex Desktop on Windows burns particular CPU core while idle if the window is visible. #30021
Description
What version of the Codex App are you using (From “About Codex” dialog)?
26.616.10790.0
What subscription do you have?
plus, previously pro
What platform is your computer?
Microsoft Windows NT 10.0.26200.0 x64
What issue are you seeing?
Total CPU percentage may look modest at first glance because the machine has 22 logical processors.
However, the main Codex.exe process continuously consumes a large fraction of one CPU core while the window is visible and idle.
In the captured log, visible idle usage averaged ~3.06% total CPU, which is about 67% of one logical core on this machine.
p95 was ~4.83% total CPU, about 106% of one logical core, with peaks around ~6.53% total CPU, about 144% of one logical core.
What steps can reproduce the bug?
This is sustained, not just a short spike. The laptop fans spin up loudly while the Codex window is visible, even when I am only reading existing text and not running any agent/tool work. After minimizing the Codex window, CPU usage drops close to zero and the fans calm down.
The load appears to come from the main Codex.exe process, not from codex app-server, node_repl, renderer, or GPU process.
What is the expected behavior?
No response
Additional information
No response
Activity
github-actions commentedon Jun 25, 2026
Potential duplicates detected. Please review them and close your issue if it is a duplicate.
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alimohajer commentedon Jul 14, 2026
Current-version datapoint from
OpenAI.Codex_26.707.9564.0on Windows 11 Pro for Workstations 10.0.26200 (Intel i9-9900, 16 logical CPUs, 64 GB RAM).Two process-time samples isolated the visible main
ChatGPT.exewindow process:In the first sample, the GPU child used 16.7% of one core and the renderer used 8.3%;
codex app-server, Node MCP servers, andnode_repleach used 0 CPU in the sampling window. Removing the idle helpers reduced working set but did not reduce main-window CPU.Important scope note: these samples were taken while a visible Codex task was active and waiting on local tool execution, not while truly idle or minimized. This is therefore a related current-build datapoint, not an exact idle reproduction. The process attribution is consistent with this issue: the main desktop window, rather than app-server or Node helpers, was the sustained CPU source.
googleoryx commentedon Aug 15, 2026
Still reproducible after restarting the app and installing the pending update to 26.810.6296.0.
Fresh post-update diagnostics:
ChatGPT.exeprocess averaged 1.388 logical cores over 10.02 seconds (6.31% total CPU).ChatGPT.exeprocesses each measured effectively 0 CPU during the same interval.%USERPROFILE%\.codex\plugins\cache\openai-bundled\chrome\latestis still being continuously deleted/recreated.%USERPROFILE%\.codex\plugins\cache\openai-bundled\chrome\26.810.50856.This is the same signature seen before the update on 26.810.4967.0, when the main process also produced roughly 0.5–1.4 GB/s of read I/O. Restarting and updating therefore did not clear or fix the loop.
The continuous junction recreation is directly observed. A stale-junction or Windows path-normalization check still appears to be a likely cause, but that cause is an inference.