raw speeds of the core 2 duo

K

konsole

Member
Lets take for instance the E8400 rated at 3.0ghz. I assumed that the 2 cores were running at 3.0ghz each making the overall total speed 6.0ghz. I was reading on another site that the number is more like 1.8 times more making this processor equal to about 5.4ghz. What say you? Do the dual cores and quad cores technically double and quadruple the rated speed respectively?
 
Last edited:
I think I can answer part of your question.

In dual-core processing, the processor housing contains two processors that operate at the same frequency, but independently of each other. What you basically have is two processors located on the same computer chip that run at cycles of up to 3 billion cycles per second with the Intel E8400 processor.

Dual-core processing allows you to multi-task (run multiple programs at the same time) better than single-core processors.

If a single program is written to run more efficiently with a dual-core processor you will really see increase in performance with that particular program.

Anyone else can feel free to add to what I have written.
 
well I know how the multiple cores work, its what the ghz rating adds up to in the multiple cores that I dont know. In other words do you have 2 cores that are running at 3ghz each or is it 1.5ghz per core or what?
 
konsole said:
well I know how the multiple cores work, its what the ghz rating adds up to in the multiple cores that I dont know. In other words do you have 2 cores that are running at 3ghz each or is it 1.5ghz per core or what?
Click to expand...

Common misconception, you have 2 cores each running at 3Ghz, you dont add/subtract for multiple cores, they are 2 cores running independently of each other for multitasking/multithreaded programs.
 
Look at it this way, take for example this scenario: You have an amd athlon 3600+ single core and a 3600+ dual core. The single core is at say 2.2 ghz, and so is the dual core. However the dual core is rated at 4.5 ghz. Why? This number is merely an estimation of the computing power that would be required for the single core to match the performance of the dual core, in an application that was dual core optimized. However running a program that isn't dual core optimized will run just as well on either, until you start to open other things and multitasking, which is where the dual core will triumph for obvious reasons.
 
you can NEVER take the speed and multiply it by the number of cores.

first of all, when you compare processors clock for clock, core i7 is faster than 45nm dual and quads. here's more examples in intel processors: core i7 > 45nm dual/quads > 65nm dual/quads > pentium dual core > pentium III. an underclocked core i7 at 1ghz is much faster than a 1ghz pentium III, so you can't look at just the clocks.

second, multi core is very different than speed. let's say you're running only 1 application on a q6600 overclocked to 3ghz. you can't say that you're running that application at 12ghz because obviously you're not going to get anywhere near those speeds. just benchmark in super pi and you'll see that generally processors with the same clocks will get around the same scores regardless of how many cores it has.
 
konsole said:
Well I know how the multiple cores work, its what the GHz rating adds up to in the multiple cores that I don't know. In other words do you have 2 cores that are running at 3 GHz each or is it 1.5 GHz per core or what?
Click to expand...


The E8400 processor has two independent processors on the same computer chip that can each operate at up to a 3 gigahertz clock speed.

The E8400 scales back its clock speed when a lot of calculating is not needed at the time. It saves power and likely extends the life of processor.
 
All dual/quad/multi-core processors have independent cores. How well they scale depends on the programs you use. A poorly written program may only gain insignificant amounts of extra performance, while a well-coded program performs a full 100% percent better on a dual-core, if not better. When multitasking and running well-optimized multithreaded applications performance can scale even more than the number of cores (i.e. when number of processing cores doubles, performance more than doubles), because there is less overhead in switching between thread (the task manager/scheduler of the operating system needs to grant each process a slice of processor time, and when the number of running threads/programs increases more resources is used to simply switching the active threads - this overhead is efffectively divided by the number of cores/processors in the system).
 
ya i figured it was 2 seperate cores capable of 3ghz each. I wonder if the performance of a 3ghz dual core is about the same as a 6ghz single core if all other specifications were equal.
 
ya i figured it was 2 seperate cores capable of 3ghz each. I wonder if the performance of a 3ghz dual core is about the same as a 6ghz single core if all other specifications were equal.
Click to expand...
Potential performance, yes. But that is only if an application is optimized to take advantage of multiple cores (multi-threading); otherwise, real-life performance will be equal to a 3GHz single-core (or slightly more, since the operating system can delegate background processes and the likes to the other core).
 
You must log in or register to reply here.
Back
Top