The Boring Tech Behind 120 FPS
Object pooling, draw-call budgets and why our rendering thread goes to sleep more than yours. A frank engineering post about the unglamorous decisions that keep frames flat.
Speed Is a Budget, Not a Feature
120fps isn't a rendering trick — it's an accounting habit. Every frame gets 8.33 milliseconds and the engine spends it like a per diem: 2ms simulation, 3ms rendering, 1ms audio and input, 2ms reserved for the moment the device decides to thermal-throttle mid-final.
The discipline that matters most is what the engine refuses to do: no garbage collection during races, no texture uploads mid-frame, no physics steps the camera can't see. Boring choices, spectacular results.
Players never notice the frames we didn't draw. That's the entire job.
The Three Unsexy Optimisations
None of these would trend on a tech blog. All of them matter more than any shader trick.
- Object pooling — every spark, gate effect and UI element is pre-allocated at launch; nothing allocates mid-race
- Draw-call budgeting — scenes cap at 60 calls; artists negotiate over budget like it's real money
- Sleeping threads — the render thread parks between frames instead of polling, cutting CPU heat measurably
- Fixed-step simulation — physics runs at a locked 240Hz regardless of display rate, so gameplay never drifts with hardware
Why 38MB of RAM Is a Design Decision
The memory ceiling exists because low-end devices kill apps that hog RAM mid-call. By keeping the whole game under 40MB at peak, Aero Racer survives the phone ringing, a text arriving and a background music app — the reality of how people actually play.
Could we spend more memory for prettier circuits? Sure. Would the game still launch in 0.6 seconds on a 2019 phone? No. The constraint is the product.
Engine Numbers
If You Only Remember Three Things
120fps comes from refusing work, not faster code — budgets beat brilliance.
Fixed-step simulation keeps gameplay identical across hardware tiers.
The 38MB ceiling is why the game survives real life — calls, texts, background apps.
Related From the Journal
Common Follow-Ups
Race the Flat Frameline
Launch the game, watch a replay at 1/8 speed — the smoothness you're seeing is bookkeeping.