__syncthreads() does in CUDA: synchronizes all threads within a block

Why do computers sometimes work faster when you click "OK"?

Imagine you're waiting for a coffee machine to finish brewing a cup. You tap "OK" to let it know you're ready to drink, but it keeps brewing even though you're ready.

Think of a coffee machine as a computer. When you tap "OK," it's like telling all the coffee-making parts to stop working at once. This way, everything stops brewing at the same time, just like __syncthreads() stops all threads in a block at once.

Example

You tap "OK" (1 tap), and all coffee-making parts stop brewing (all threads stop executing).

Remember this

__syncthreads() ensures all threads in a block finish their tasks simultaneously.

Text adapted from Wikipedia, licensed under CC BY-SA 4.0.

Related concepts

Thread block (CUDA programming)

Thread blocks can contain up to 1024 threads as of March 2010

List of gay characters in animation

How can you add numbers safely in a busy computer?

cooperative groups enable in CUDA: flexible thread synchronization patterns

Cooperative groups enable flexible thread synchronization patterns in CUDA

Triton differs from CUDA

Why does a super-fast computer sometimes run slower than a regular one?

CUDA

CUDA enables parallel computation on GPUs

Dynamic random-access memory

DRAM requires periodic refreshing to maintain data integrity

Swipe through 100 ML concepts daily

Open Pocket Polymath