"Actually Speed per Core" ...


Aug 1, 2009
Hi everyone,

I have been looking for this answer for a long time. I hope someone can guide/tell me the answer.

With the movement of more core on one die, from Dual-Core, Core2Duo, Core2Quad, and now the i5 and i7 series, I'd like to know what's the actual speed per core. For example, Core 2 Duo E6600 2.4Ghz, does it mean each core running at 2.4 Ghz ? or the TOTAL speed of the 2 cores running at 2.4 Ghz? so, each core is running at 1.2Ghz ..

For another example: Core 2 Quad Q6600 2.4GHz. what's the situation here? If the total speed is 2.4Ghz, then each core is 600MHz ?

A friend who was one of the engineers of Intel who specificall work on the Pentium M notebook processor. He was one of the team lead of processor architects. He said that what we see the multicore processors should be the "total" speed, not the individual core. One of the main reasons why it is faster at the same speed is because Intel makes the codes and design a lot more efficient and sync a lot better between the cores. So, it can handle multi tasks better.

However, he is not with the processors team anymore, and can't tell me more specify.

So, I'd like to know if we can validated what is the true speed of each core.

Secondly, how do OSes behave with multi core situation? do developers still have to explicilty write codes for multi cores processing or the complier will kind of automatically takes care of it even without expliciltly call out the instructions.




Jul 31, 2009
In a multi-core processor, the rated clock speed is the speed each core individually is running at. An i7 920 at stock speeds has four cores, each running at 2.66GHz.

Some of the newer i5 and i7 processors have a feature that lets them raise the speed of one or two cores when the software is only using one or two cores--this lets the processor speed up for that software while not overheating by raising the clock on all four cores.

And I don't know a lot about coding, but as far as I know, support for more than one thread in an application has to be specially coded. Someone else will correct me if I'm wrong...


Mar 4, 2009
if u get a Core 2 Quad at 2.8 ghz

the proc speed is 2.8 ghz

and the cores operate at that frequency

Core 1: 2.8
Core 2: 2.8
Core 3: 2.8
Core 4: 2.8

they aren't 700 mhz each.

OSes use two or one core to do the main task such as playing a game or browsing etc. the uses the rest to do background tasks

but if a game or task requires 4 cores it will use all 4 to do that one task, where the system will slow down a bit because then the background task has to be handled as well as the main task so the 4 cores have to do 2 things each

same with dual core just less cores

and yes as the person before me said, multi core utilization requires special coding which takes a ton longer and is more expensive, other than that i don't know anything else