Your apps first
Turn it on and your agents step aside whenever you work. The trade-off: agents slow down while you do.
It’s off by default. Turn it on in Settings › Performance › Your apps always come first, and every agent runs below your apps, so the apps you’re using stay smooth.
What it does
- Every agent runs at macOS background priority, including the one you’re viewing. Tools, builds, tests, servers and local model jobs it starts inherit that.
- macOS keeps these tasks on the efficiency cores at the lowest scheduling priority, and slows their disk and network use.
- The footer reads Agents yielding to your apps while it’s in force.
The trade-off
Your apps stay smooth, and your agents get slower. Under heavy load that’s a lot: in our benchmark, 32 busy agent processes kept about 5% of their CPU throughput, and a single agent running four busy processes kept about 28%. No agent starved, but a long build can hit a tool timeout while you’re actively using your Mac.
Giving the Mac back to your agents
When you’re away, agents return to normal priority: Return agents to normal priority when I’m away for N minutes (default 5, or Never). When you’re back, they step aside again within a few seconds. Switch the setting off at any time and XAgents returns to its standard efficiency mode: agents you aren’t viewing stay on efficiency cores, and the one you’re viewing runs at full speed.
What we measured
| Foreground app, under agent load | No agents | Setting off | Setting on |
|---|---|---|---|
| Janky frames | 1.0% | 86.9% | 0.6% |
| Frame time, 99th percentile | 15.8 ms | 50.4 ms | 15.5 ms |
| Agent CPU work | — | 7,335 units/s | 370 units/s (5%) |
We ran 8 agent-like workloads, each with four CPU-bound tool processes and a disk writer, beside four foreground apps drawing at 60 Hz. The figures are medians of two 10-second rounds per setting on a 15-core Mac that was also busy with other work. Input and disk latency were unaffected either way at this load.