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Core i7, 4 or 8 cores?

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October 9, 2009 1:37:16 PM

Hey,
I have read about the new Intel Core i7 processors. Have they realy 8 cores? I have found a text, there say the people, that the new processors are 4cores but the laptop thinks there are 8cores. An their performance are great for gamers. What do you think? And can cou explain me that, with the 4/8 cores?
I found it here:
Core i7 processors

More about : core cores

a b à CPUs
October 9, 2009 1:58:13 PM

actually there are no 8 core processors as of now... a six core processor is expected early next year.... there are core i7 processors with HT technology that have 8 threads... something like a core gets two partitions where 2 things can be done simultaneously... hence 2 X 4 = 8 threads are 8 apparent cores...

they are proved to be great performers in not just games but in about every processing aspect...

these are all desktop processors and are soon expected to come to mobile(laptop) platforms...

Hope the reply was helpful...
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a b à CPUs
October 9, 2009 2:03:38 PM

4 Physical cores - 8 Logical cores through a process called 'Hyperthreading'.

(Highly complicated topic - so I'm issuing a gross oversimplification alert - I *am* taking short cuts in order to explain the idea, not necessarily the true technical detailia.)

Understand there are multiple steps for an instruction to be processed. Once you have that, then it's fairly easy to grasp that when instruction A is at step #4, then steps 1, 2, 3, and 5 are idle. OK? The next 'improvement' would be to take the next instruction and hand it to step 1, knowing that the first instruction is already safely out of the way. So, now you have a processor working on two instructions at once... Yah? Groups of instructions that run as a 'logical process' still need to be run as a single entity (a "Thread").

Well... Because these Threads represent a single logical process, they obviously have to from the same Application. The way most/older computers have handled multiple applications is put everything on hold except the one they are working on at that instant. From there, switch back and forth. It happens really fast, so human beings perceive it as doing both things at once. But that's not really the case: it does one. Then the other. But never two different applications at the same instant.


The idea behind hyperthreading is to create some logic which can tell which Threads belong to which Application. Once we can track that, then it becomes possible to run two independent 'Threads' at once. Earlier we had two instructions from the same 'Thread' being worked on at the same time, correct? Being able to tell which instruction belongs to which thread means we can now run two Threads at the same time - just so long as individual instructions aren't at the same step at the same time.

Since the single (Physical) core can run two Threads at the same time, it's understood and displayed by the operating system as two processors.

There is a certain amount of overhead needed to keep track, and the software you are running needs to understand how to operate in a 'Threaded' environment to take best advantage. So it doesn't scale perfectly. But it *is* a pretty crafty way to get more work out of the same (physical) asset.


Here's a pretty good article at ARS Technica on the topic if you want to know the deeper nuts and bolts.


October 9, 2009 2:04:42 PM

Tank you. I`a interessted in the laptop processors, because i think about to buy an Alienware laptop with the core i7 720QM
October 9, 2009 2:08:21 PM

Thats like Java?
a b à CPUs
October 9, 2009 2:14:07 PM

Java is a programming language and environment. And while you can use Java to write Code which is "thread~safe", what I was talking about happens on a Hardware level.
October 9, 2009 2:20:20 PM

Yes, i know. But I mean the idea is like Java. And the HT musst be programmed to, for hardware...but the idea is like the same
a b à CPUs
October 9, 2009 2:50:25 PM

Yah - The concept is the same - basically the complimentary parts (software/hardware) of the same puzzle.
October 9, 2009 2:56:12 PM

Not that you tink i dont know about the difference about hardware and software. I am female jey, but i am a programmer, that because i think on java.... sometimes to much xD
a b à CPUs
October 9, 2009 3:00:56 PM

Gender has nothing to do with it :)  Simply that I didn't know your level of expertise, so I was trying to give a very simple answer to a complex topic. Hell - Now that we've gotten this far, I'm pretty sure from here you'd be better off without me boring you with oversimplifications.... <grin>
a b à CPUs
October 9, 2009 11:14:02 PM

There are six cored processors but no the i7, the i7 actually has 4 physical cores and 4 virtual cores (Hyperthreading), its a technology to make multiple threads run on physical cores which has its benefits. The Operating System however actually thinks its 8 Cpu's or Cores.
October 12, 2009 6:22:23 AM

Thank You
!