Dual core - dedicated RAM?

Ted Oak

Junior Member
Feb 5, 2007
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I heard that in a dual core CPU (Pentium D 945) system with two memory sticks and running software multiprocessing capable, each module is dedicated to one CPU (core), so if one CPU (core) is idle, the corresponding memory module woul be idle also, which would mean that if my system has 2 x 512 Mb RAM (1 GB total), 512 Mb would be the limit for each core. In other words, my system would have 512 Mb for real.

Anybody knows something about it?
Thanks for any help.
 

sonoran

Member
May 9, 2002
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You should stop listening to whoever told you that, because they have no clue what they're talking about. The 1GB would be accessible by either core, dependent on how the OS decided to allocate it to the running processes.
 

Diogenes2

Platinum Member
Jul 26, 2001
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Originally posted by: Ted Oak
I heard that in a dual core CPU (Pentium D 945) system with two memory sticks and running software multiprocessing capable, each module is dedicated to one CPU (core), so if one CPU (core) is idle, the corresponding memory module woul be idle also, which would mean that if my system has 2 x 512 Mb RAM (1 GB total), 512 Mb would be the limit for each core. In other words, my system would have 512 Mb for real.

Anybody knows something about it?
Thanks for any help.


What sonoran said..

Both cores share one memory controller, bus and etc.. You would have
to have two memory subsystems to accomplish what you are alluding to..
 

IntelUser2000

Elite Member
Oct 14, 2003
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Hey guys, don't bash people without complete information.

Ted Oak: Your suspicions aren't completely unfounded. Look here: http://www.digit-life.com/articles2/cpu/rmmt-l2-cache.html

You can see each thread can get equivalent amount of bandwidth, making the total bandwidth greater than the single thread bandwidth, but less than double.

I don't know about X2 on Socket 939, but on the AM2 platform, the CPU has two 32-bit memory controllers.

But the other people are right Ted, one core of a CPU can access all capacity of the memory, just not all the bandwidth.
 

Diogenes2

Platinum Member
Jul 26, 2001
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As asked, the suspicions were completely unfounded..

Allocatiing dedicated memory space is not the same as each core accessing one DIMM in a two DIMM configuration ..

And of course, two cores sharing memory will not achieve the same bandwidth ( per core ) as a one core CPU ..