What is the difference between temporary multithreaded and superthreaded?

Question

There are two terms:

• Temporary multithreading : in fine-grained temporary multithreading, the main processor pipeline can contain several threads, while context switches are effectively executed between (for example, in a barrel processor ). A cylinder processor is a processor that switches between threads of execution in each cycle.

• Super-threading : this is a type of multithreading that allows you to execute different threads on the same processor, without executing them by default at the same time. 1 This qualifies it as temporary or temporary multithreading rather than simultaneous multithreading (SMT). This is motivated by the observation that the functional blocks of the processor sometimes remain idle when executing instructions from a single thread due to events with a large delay. Super-threading seeks to use the remaining unused processor cycles by executing instructions from another thread until the previous thread is ready to resume execution.

The main difference between TM and ST is that temporary multithreading (fine-grained) uses C-slowing and switches between threads for each cycle, but Super-threading switches between threads not every cycle and only when the functional blocks of the processor remain inactive when executing commands from one thread due to events with a long delay?

What is the difference between temporary multi-threaded (fine-grained) and super-thread?

Answer 1

Temporary multithreading can be in the form of fine-grained or coarse-grained multithreading. Fine-grained multi-threaded context switches with a fixed interval of fine grain (for example, each cycle). Coarse-grained multi-threaded network containers will switch to long-delayed events (for example, LLC cache misses).

Simultaneous multithreading, on the other hand, has no idea about thread switching. Multiple threads can be started simultaneously.

A picture is worth a thousand words. Take a look at slides 5 through 7 here . It has images for all 3 methods and compares them well.

As other people have said, super threading is not a general term, and it seems to me that it looks like a coarse-grained TM.