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london

 
Member Since: Aug 11, 2006
Posts: 21
london is an unknown at this point

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Quote:
Originally Posted by ezhangin
It appears you need to remember a few things about computers. First off, when you say Opterons don't share RAM and front side bus you are wrong and right at the same time. You are getting dual-core and dual processor computers confused. Dual proc computers do not share ram, or anything for that matter. Dual-core computers share RAM and cache. This makes them cheaper but inevitably slightly slower than a true dual processor computer.

As for the mac pro being a piece of junk, that is not true at all. The processors in their may be more powerful than you think, considering they are core 2's. The Xeon 5100 series are core 2's, just renamed for being server chips (because of their memory!). So therefore the MacPro is both dual-core and dual processor.
No your wrong dual cpu socket Xeons share the shame memory and memory bus. the bus from the ram to the CPUs is the same. opteron have a completly seperate memory banks for each CPU. Do you home work. if you take the Ram away from one Opteron CPU it wont work it cant share the memory from the other CPu's memory bank.( it wont even boot if there is no Ram for one cpu.)
If you put just one stick of ram in the Mac pro, both CPUs will use it.

If a Mac Pro had a seperate memory bank for each CPU it would have a theoretical bandwidth of 1600 Gb/s.and going on the real world test of the Mac Pro. Even if it did have a seperate memory bank/bus for each CPu it would still only have a real world memory bandwidth of 8584 GB/s still well short of my 3 year old single core Opterons.

I really wanted to like the Mac pro. i wanted one. but facts are facts. I know a 2.6Ghz xeon is faster then a 2.6Ghz opteron. In raw cpu speed. but in means nothing if your memory bandwidth is jank. memory bandwidth is crutial to overall real world performance.