Most of what makes a board fast is chosen for you. This page says what is chosen, what is left to set, and how to read the numbers.

Start from a board

A board package (deki-lilygo-boards, say) carries the settings its board runs best with. Pick the board as your target and you have them; there is nothing to tune.

Board	Every demo scene	Frames
LilyGO T-Display S3 AMOLED	59.6 fps (its panel's refresh)	never tear (TE line)
LilyGO T-Deck Plus	60 fps	never tear (the panel's scanline)

The rest of this page is for a board of your own, or for finding out why a scene is slow.

What chooses itself

Each of these is decided on the device when the game starts. The boot log has one line for each, saying what was chosen and why.

What	How it is chosen
Whole frames or strips	Whole frames when the framebuffer fits in internal RAM with room to spare; strips when it does not. Strips are drawn into internal RAM a few rows or columns at a time, which is much faster than drawing a whole frame in PSRAM. (Rendering settings, frameMode.)
Sending from the other core	On a dual-core chip with the memory for two frame copies, each frame is sent while the next is drawn. Otherwise frames are sent as they are drawn. (asyncPresent, on.)
Tearing	With a TE line wired (tePin), frames follow the panel's refresh signal. Without one, the panel's scanline is read back instead (scanlineSync, on). A panel that cannot be read back is sent as drawn, and can tear.

What a board sets

These describe how the board is wired, which the device cannot find out.

Setting	Set it to
controller, busType and the pins	What the board's schematic says.
spiWriteHz (parallelWriteHz)	The fastest clock the panel takes. Most ST7789 modules take 80 MHz; on a parallel bus, 20 MHz is safe.
tePin	The GPIO the panel's TE output is wired to, if it is. The best way to stop tearing.
readsOnMosi	On when the panel answers on its data line instead of MISO (the T-Deck's does). Only matters without a TE line.
initSequence	The panel module's own start-up, when the controller's default looks wrong (washed out, a ghost of the last image).

Project settings worth knowing

Setting	When to change it
dirtyTileTracking	On when most of the screen stays still and nothing is drawn over the whole screen every frame (a full-screen background is). Then only what changed is sent.
bandRows	The size of a strip. Bigger strips walk the scene fewer times but take more internal RAM. 40 suits most screens.
frameMode	Leave on Auto, unless you have measured that the other mode is faster on your board.

Rarely needed: usePsram and doubleBuffer (where the engine draws whole frames), and spiReadHz (the T-Deck's ST7789 reads reliably at 10 MHz).

Reading the numbers

DEKI:STATS on the serial port, or the device_stats tool, prints one line:

fps=60.0 frameMs=16.66 updateMs=1.00 renderMs=7.80 presentMs=3.36 internalFree=50807 frameMode=whole

updateMs: game logic. A scene that has just opened loads here.
renderMs: drawing. In strips it also covers sending, since each strip is sent as soon as it is drawn.
presentMs: handing the frame to the display. High means the display is still sending the last one: the bus is the limit, not drawing.
internalFree: internal RAM left, which Wi-Fi, Bluetooth and strips all take from.

DEKI:PROFILE breaks drawing down by component and by blit path, for finding the one thing in a scene that costs the most.

A frame rate locked at the panel's refresh (59.6 to 60.3 Hz) is the best a tear-free board can do: frames wait for the refresh rather than tear.