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What about new MacPro with 3.2 Nehalem
- Thread starter DantesAID
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It also could be because to go from 2.93GHz to 3.2GHz the TDP jumps from 95W per processor to 130W per processor. Maybe Apple couldn't/didn't want to deal with that much heat.
Well both the old 3GHz quads were 120W and the 3.2GHz was 150W so while possible I'm not sure that is the issue.
Looking at the size of the heatsinks Apple's used I don't think so, plus it looks like you have 1 fan at the front and back creating a wind tunnel effect.
I don't think "too expensive" is in apple's vocabulary. It was probably some other reason like heat/cooling.
I'd think available quantities has more to do with it. Limited production due to one operational 45nm fab, and the grading is likely quite stringent. So not every part produced would pass.
Somehow, I don't think an extra 20W/CPU TDP would prevent Apple from using it.
I for one really hope that it will comeout soon.
Then everyone who ordered a 2.93 eight-core would return their computers. Apple won't do it.
Not likely
The 3.2 has a different thermal envelope. With the current case design, you wouldn't benefit from the built-in automatic overclocking since you would be hitting the thermal limits all the time.
35W x 2 = an extra 70 watt light bulb's worth of heat to get rid of. That's a very big deal and they would need to design it into all the cases or end up with a separate design.
Everybody just sit back and watch what Snow Leopard does with the extra virtual cores and Turbo Boost (?). Hopefully then you'll stop nit-picking over an extra 100 MHz.
The 3.2 has a different thermal envelope. With the current case design, you wouldn't benefit from the built-in automatic overclocking since you would be hitting the thermal limits all the time.
35W x 2 = an extra 70 watt light bulb's worth of heat to get rid of. That's a very big deal and they would need to design it into all the cases or end up with a separate design.
Everybody just sit back and watch what Snow Leopard does with the extra virtual cores and Turbo Boost (?). Hopefully then you'll stop nit-picking over an extra 100 MHz.
So the new internal layout has worse cooling? The old 3.2Ghz processors had a 150W TDP, the new ones are 130W.
Virtual cores? you mean threads? Threads and Turbo Boost are processors feature already available for the Xeons in the new Mac Pro, not from Mac OS X.
I think you right...
The moment DELL, IBM and the rest of them will start selling they're workstation with 3.2Ghz in a month or two. Apple will have to do something about it.
I used the term "virtual cores" for effect. 8 cores with HT is not the same as 8 cores wo/HT if the OS knows how to use it.
HT support is present in the processors, but the OS must be smart enough to manage HT properly. For example, the first "core" will expose ID's 0 and 1, the second "core" 2 and 3, etc. An HT-aware OS will use ID's 0, 2, 4 and 8 before going back and using 1, 3, 5 and 7. Windows XP needed the same optimizations.
Also, you need to do much tighter management of wait loops so that the "partner thread" for a core can have better access to it. There are also certain threads that can be optimized to use the units that can be easily shared between partner threads. A core has some resources that are duplicated, other resources that are shared. If, for example, you know that your driver threads don't need the unique resources, those threads can be given affinity to be set up as partner threads.
You get much more from HT if you know what you're doing than if you use it as though you have just have twice the number of simultaneous threads. I've managed a significant performance increase on certain hand-assembled pieces of code for Microsoft Windows, enough to make the virtual thread just as good as having another full "core."