Tag: performance

Five of the head unit's emulator cores came from a microcontroller project. I replaced four of them, chosen by running every game on the card and timing the winners on the car's own Cortex-A9.

Replacing a millisecond sleep with a microsecond deadline removed frame overruns in three hosts. Master System's fast Z80 had never reached the QNX build.

The library took 92 seconds to come back after every game. The first plausible fix did nothing; two metadata walks and an eager collection were the cause.

I blamed the display, then the textures, and both times I was wrong. Isolating one variable at a time found eight bits of shader arithmetic.

Rusty Nail became a QNX launcher for eleven emulator paths on the MIB2. N64 failed on performance and then on a graphics plugin abort.

A phone app that talks to the dashboard panel rather than the car, and the fault codes a battery disconnect wrote into eight modules.

The SNES core was losing four million cycles a frame waiting on a sound chip on another board. Predicting the answer lifted Super Mario World from 35 to about 50 fps.

Days optimising the HDMI coprocessor because every symptom said it was holding the SNES back. The measurements pointed at the wire instead.

The from-scratch SNES core matches the reference emulator to the cycle. Five optimisations measured on hardware, and a profiler that says the problem is memory.

One day of hardware A/B tests on the H753. The biggest single win was a compiler flag I should have set weeks ago.