While true Vs RunService Performance

[RobloxerXx23]

Is using a while true do or using RunService better for performance?

I would assume it is while true do loop as it doesn’t fire every frame however, I could be wrong. Note: I understand the difference in each method however, strictly speaking, which one is better for performance.

[uvic1rn (Sarah)]

A while true do loop runs repeatedly until you break it. Listening to RunService.Heartbeat runs something every frame. They are completely different, so you’ll have to explain more about what you’re doing.

This code:

local previousTime = tick()
while true do
    local currentTime = tick()
    model:TranslateBy(Vector3.new(0, 2 * (currentTime - previousTime), 0))
    previousTime = currentTime
end

Will not smoothly animate the model. It will crash your script after about 30 seconds because you are never pausing your script for other scripts to run.

This code, however:

RunService.Heartbeat:Connect(function(timePassed)
    model:TranslateBy(Vector3.new(0, 2 * timePassed))
end)

Will move the model up at a rate of 2 studs per second. Note that this code is basically identical to:

while true do
    local timePassed = RunService.Heartbeat:Wait()
    model:TranslateBy(Vector3.new(0, 2 * timePassed))
end

Which is identical to:

while true do
    local timePassed = task.wait()
    model:TranslateBy(Vector3.new(0, 2 * timePassed))
end

[capsori (cap)]

it really depends on the use case here,
each should be used depending on what you need
so you can’t really compare “performance” between them

[RobloxerXx23]

Replying to:

@uvic1rn

A while true do loop runs repeatedly until you break it. Listening to RunService.Heartbeat runs something every frame. They are completely different, so you’ll have to explain more about what you’re doing

@capsori

it really depends on the use case here,
each should be used depending on what you need
so you can’t really compare “performance” between them

---

For example, if I had a bobbing animation, in terms of performance which one would be better (I understand that RunService would give a smoother result):

while task.wait() do
	Part.Position = Vector3.new(0, math.sin(tick()), 0)
end

game:GetService("RunService").Heartbeat:Connect(function()
	Part.Position = Vector3.new(0, math.sin(tick()), 0)
end)

[uvic1rn (Sarah)]

They are equivalent in terms of smoothness and performance. task.wait() is equivalent to RunService.Heartbeat:Wait().

@RobloxerXx23

while task.wait() do
	Part.Position = Vector3.new(0, math.sin(tick()), 0)
end

For readability, I would recommend:

while true do
    task.wait()
    Part.Position = Vector3.new(0, math.sin(tick()), 0)
end

But you don’t have to.

[capsori (cap)]

for a bobbinh animations,
run service is the way to go, since it runs every frame
which grants a smoother feel

[RobloxerXx23]

So both while true and RunService Yeilds the same results in terms of Performance?

[RobloxerXx23]

I understand that however, which one is better for Performance if we were to ignore the smoother feel

[uvic1rn (Sarah)]

Yes. They do literally the same thing.

@Roblox

Yields the current thread until the given duration (in seconds) has elapsed, then resumes the thread on the next Heartbeat step. The actual amount of time elapsed is returned.

If no duration is given, it will default to zero (0). This means the thread resumes on the very next step, which is equivalent in behavior to RunService.Heartbeat:Wait()

Unlike the deprecated global wait, this function does not throttle and guarantees the resumption of the thread on the first Heartbeat that occurs when it is due. This function also only returns the elapsed time and nothing else.

— task.wait documentation

[RobloxerXx23]

Okay, thanks for the information!