Performance issues

Question

### What version of Codex CLI is running?

codex-cli 0.131.0

### What subscription do you have?

Pro 5x

### Which model were you using?

gpt-5.5

### What platform is your computer?

Darwin 25.2.0 arm64 arm

### What terminal emulator and version are you using (if applicable)?

cmux

### Codex doctor report

```json

```

### What issue are you seeing?

When I send a prompt, application noticeably slows down (assuming RAM churning)
Launching sub agents as well.

### What steps can reproduce th