Ok, I know I might have read somewhere on here about this but I cant seem to remember where. Anyhow, what is the diference between two separate 2.3 ghz chips, and a single dual core 2.3 ghz chip? Is the dual core better and why?
Ok, I know I might have read somewhere on here about this but I cant seem to remember where. Anyhow, what is the diference between two separate 2.3 ghz chips, and a single dual core 2.3 ghz chip? Is the dual core better and why?
I encourage you to check to "Date for next powermac" thread on Future Hardware - there is plenty on dual-core there. Advantage: two processors on the same chip can work together - share data etc - very quickly, more so than two chips with one processor each. Disadvantage (?) - 2-chip machines had separate data bus for each processor (good), whereas single dual-core machines have one data bus to serve both processors, as I understand it (both on a single chip).
Such is my understanding. There are also other cache and other differences, the details of which I am unaware. Some early comparisons have been made - see here: http://media.99mac.se/g5_dualcore/
In terms of the dual core chips that Apple is using, they also have double the amount of cache per core (1MB instead of 512K). That should mean quite a significant performance boost.
The above is not an inherent advantage of dual core chips, after all IBM could also have included 1MB of cache in the single core chips, but they did not.
How about heat? Do the dual core chips use less power, making them cooler than two single core chips? Are the fans in the 2.0 and 2.3 Ghz models likely to run slower or less often than in previous models as a result?
<edit> Does having only one bus make the whole system cooler?
In terms of the dual core chips that Apple is using, they also have double the amount of cache per core (1MB instead of 512K). That should mean quite a significant performance boost.
The above is not an inherent advantage of dual core chips, after all IBM could also have included 1MB of cache in the single core chips, but they did not.
IBM has a page (sorry, unable to link it here, but it is www.-03.ibm.com/chips/news/2005/0707-power.html) in which they say that they achieve double the performance of the PPC 970FX, for their server applications, due to the 1MB L2 cache, for each core. This is one page announcing the 970MP back some time ago.
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Originally posted by hypoluxa
Ok, I know I might have read somewhere on here about this but I cant seem to remember where. Anyhow, what is the diference between two separate 2.3 ghz chips, and a single dual core 2.3 ghz chip? Is the dual core better and why?
I encourage you to check to "Date for next powermac" thread on Future Hardware - there is plenty on dual-core there. Advantage: two processors on the same chip can work together - share data etc - very quickly, more so than two chips with one processor each. Disadvantage (?) - 2-chip machines had separate data bus for each processor (good), whereas single dual-core machines have one data bus to serve both processors, as I understand it (both on a single chip).
Such is my understanding. There are also other cache and other differences, the details of which I am unaware. Some early comparisons have been made - see here: http://media.99mac.se/g5_dualcore/
The above is not an inherent advantage of dual core chips, after all IBM could also have included 1MB of cache in the single core chips, but they did not.
<edit> Does having only one bus make the whole system cooler?
Originally posted by Robin Hood
In terms of the dual core chips that Apple is using, they also have double the amount of cache per core (1MB instead of 512K). That should mean quite a significant performance boost.
The above is not an inherent advantage of dual core chips, after all IBM could also have included 1MB of cache in the single core chips, but they did not.
IBM has a page (sorry, unable to link it here, but it is www.-03.ibm.com/chips/news/2005/0707-power.html) in which they say that they achieve double the performance of the PPC 970FX, for their server applications, due to the 1MB L2 cache, for each core. This is one page announcing the 970MP back some time ago.