Performance
Only measured figures, with their dates and conditions. Nothing here is a promise for your Mac.
| Measurement | Result | Conditions | Date |
|---|---|---|---|
| Career race (Zone Heat 1, Circuit), hand test 4 | 58.5 fps average over 118 two-second intervals (about 4 minutes); lowest interval 29.6 fps, just after the race’s opening cutscene | MacBook Air M5, 720p internal resolution, fullscreen | 2026-10-23 |
| Scripted Quick Race | 57.6 fps average, no interval under 30 fps (lowest 42.8) | MacBook Air M5, with frame dumps on (they add a stall every 60 frames) | 2026-10-23 |
| Same, without frame dumps (soak run) | 59.5 fps average | MacBook Air M5 | 2026-10-23 |
| Free-roam, hand test 3 | 15 minutes without a crash, hang or watchdog report | MacBook Air M5 | 2026-10-23 |
The ROADMAP’s racing criterion (M7) asks for a stable 30 fps or better over 10 minutes of racing, from frame-time logs. That hasn’t been measured yet.
Under CPU load from other apps
Section titled “Under CPU load from other apps”ReCarbon raises the game threads that drive each frame (the ones that present a frame or read the controller) to macOS’s “user-initiated” priority. It never lowers a thread that already runs higher. Measured before and after, with the same scripted Quick Race:
| Measurement | Before | After | Conditions | Date |
|---|---|---|---|---|
| Stalls of 100 ms or more per run | 5.3 (3, 9, 4) | 0.3 (0, 0, 1) | MacBook Air M1 (8 GB), 720p internal resolution, six background busy loops, 3 runs each, 185 s of racing per run | 2026-10-25 |
| Longest frame | 137 ms | 99 ms | same | 2026-10-25 |
| Average frame rate | 40.6 fps | 40.6 fps | same (the load, not the priority, sets the frame rate) | 2026-10-25 |
| Game CPU use | 1.75 cores | 1.94 cores | same: the frame threads now run instead of waiting | 2026-10-25 |
| Without background load | no difference (0 stalls of 100 ms or more in 9 runs) | MacBook Air M1 | 2026-10-25 | |
| Packaged app, Game Mode on, no background load | 39.8 fps in the race, 0 stalls of 100 ms or more, no audio gaps | MacBook Air M1, fullscreen, scripted Quick Race | 2026-10-25 |
Measured on one Mac with a synthetic load. It doesn’t fix the stalls below, and it hasn’t been measured on other Macs yet.
Known stalls
Section titled “Known stalls”Short stalls still happen: see Known issues. They are recorded honestly, not cut out of measurements.
Settings that affect performance
Section titled “Settings that affect performance”All in Settings (F1); see Settings:
- Internal Resolution: the 3D scene’s resolution. 1x is the console’s 720p.
- Frame Rate: 60, 30, or Auto (60, or 30 while the device is hot or can’t hold 60).
- Asynchronous Shaders: skips an object for a frame or two while its shader compiles, instead of stuttering.
- Performance Overlay: shows the frame rate and frame time in a corner.
A RetroNative project.
ReCarbon is an unofficial fan project. It is not affiliated with, endorsed by or sponsored by Electronic Arts Inc. or the Need for Speed brand. Need for Speed and Carbon are trademarks of Electronic Arts Inc. and are used here only to describe the game. No game files are included or distributed: you need your own legally obtained copy of the Xbox 360 disc.