Pentium Pro / Hyperthreading / Pipeline

**leon m** · 24-10-2008

Hello,

I read that the characteristics of the Pentium Pro was able to execute 5 instructions at the same time. How is this different from the hyperthreading?
And what is the difference between a processor and hyperthreading to 2 pipelines?

Thank you in advance for your answers

**leon m** · 24-10-2008

I read here that I found very well done.
For comparison hyperthreading / pipeline, I'll try to summarize:

pipeline and hyperthreading are two complementary ways to optimize the use of CPU resources.
the hyperthreading applies in a pipeline
The pipeline is designed to help optimize the treatment of a direction while hyperthreading can handle two simultaneous threads, thread being processed more quickly through the pipeline
hyperthreading allows the use of unused resources generally (since a classical education will use only 35% of resources.

So I have three questions:

That's where I completely wallow?
Regarding the 65% unused, is to increase the number of pipelines it does not significantly reduce the "loss"?
if the answer to the above question is yes, I still find it hard to see the benefits derived from hyperthreading compared to x pipelines?

Now turn to the case of Pentium Pro and its 5 instructions executed simultaneously.
This means that there were 5 pipelines?

**robodude** · 24-10-2008

for hyperthreading, I think the processor and a 2 caches can move from one to another quickly (without going through the memory controller surely)
and therefore able to manage 2 different things more easily like a dualcore (except that there is a trick to make the calculation behind)

**opaper** · 24-10-2008

The Pentium Pro has five different ports of execution so it can execute five directions at once but it depends on the instructions that are available.
The hyperthreading is used to give more choice to the processor: it will draw the instructions in two different programs, alternating between the two at each cycle.