Optimize Lua Performance in FiveM

A good FiveM server must be able to run scripts without causing lag. Most problems come from inefficient Lua code.

Problem 1: Thread running every frame

-- Consumables: Runs 60 times/sec.
Citizen.CreateThread(function()
    while true do
        checkZones()
        Citizen.Wait(0) -- BAD
    end
end)

-- Better: Run 2 times/sec.
Citizen.CreateThread(function()
    while true do
        checkZones()
        Citizen.Wait(500) -- GOOD
    end
end)

-- Best: Dynamic wait
Citizen.CreateThread(function()
    while true do
        local nearZone = checkZones()
        Citizen.Wait(nearZone and 100 or 1000)
    end
end)

Problem 2: Spam MySQL Queries

-- Cache data instead of querying every time
local playerCache = {}

AddEventHandler('playerJoining', function()
    local src = source
    MySQL.Async.fetchAll('SELECT * FROM users WHERE identifier = @id', {
        ['@id'] = GetPlayerIdentifier(tostring(src), 0)
    }, function(result)
        playerCache[src] = result[1]
    end)
end)

AddEventHandler('playerDropped', function()
    playerCache[source] = nil
end)

Problem 3: Not using Local Variables

-- slower than: lookup every time
for i = 1, 10000 do
    math.random()
end

-- 30% faster: cache local
local random = math.random
for i = 1, 10000 do
    random()
end

Problem 4: Draw every frame without checking the distance.

Citizen.CreateThread(function()
    while true do
        local playerCoords = GetEntityCoords(PlayerPedId())
        local targetCoords = vector3(100.0, 200.0, 30.0)
        
        if GetDistanceBetweenCoords(playerCoords, targetCoords, true) <= 10.0 then
            DrawText3D(100.0, 200.0, 30.0, "Press button")
            Citizen.Wait(0) -- when near draw every frame
        else
            Citizen.Wait(500) -- far reduces poll
        end
    end
end)

Performance Checklist

• No Thread runs Wait(0) unnecessarily.
• MySQL queries are cached whenever possible.
• Use local variables for frequently used functions.
• Draw calls have a distance check first.

Summary

Lua performance optimization isn't difficult. Just know what's using up a lot of resources. Caching data, reducing poll frequency, and using local variables can have a big impact on performance.