hypertheading or threading?

[ARICH5]

ive noticed latley there is different wording used between HYPERthreads, hyperthreading, more threads, corethreads, 2-threading.

with the difference? does intel have hypertheading? AMD have threading?

whats the syntax?

 

[chemmajorp53]

Hyperthreading (Intel) and SMT (AMD) are both essentially the same thing, which is running two virtual "lanes" through a physical core to allow for more instructions to be solved at the same time. Cores and hyperthreads are both technically threads to the operating system. A hyperthread or virtual thread isn't as powerful as the full core, but can be run at the same time. So maybe if you run 8 threads instead of 4 you can increase productivity by 50% if all the threads are saturated.

 

[gamerk316]

Hyperthreading is just a form of SMT, both of which attempt to increase throughput by allowing additional threads to execute of the necessary CPU hardware they require is not in use.

 

[ARICH5]

whoa, another one. vitual lanes?

 

[gamerk316]

whoa, another one. vitual lanes?

The easiest way to explain it is like this: A CPU core consists of two parts. The first part are the CPU registers that holds the cores Architectural State. The second part consists of the Execution Resources that perform actions on the data stored in the CPUs registers.

In a SMT capable CPU, the Architectural State (registers) are duplicated, but the Execution Resources are not. As a result, the Operating System sees double the amount of CPU cores, and can schedule twice as many threads as a result. Because the cores hardware is only partially duplicated, we call these cores "Virtual Cores" to differentiate them from standard CPU cores.

Because the Execution Resources are not duplicated, the OS thread scheduler needs to be aware the processor is SMT capable so as not to schedule threads that need access to the same Execution Resources at the same time, which would result in one thread stopping while the other finishes, providing no benefit (and in some cases, negative benefit). But when handled properly, you can double throughput while only duplicating as little as 10% of a cores hardware.

 

[chemmajorp53]

Hyperthreading is a verb, Hyperthreads are the noun of that verb. More threads just refers to how many cores a processor appears to be to windows. I've never heard anyone say "corethreads" or "2-threading." The process is called "Simultaneous multithreading" or SMT, Intel's brand name for it is hyperthreading, AMD just calls it SMT.