Re: Re: Re: irony is often lost
Originally posted by ffakr
Most laptops use 2 SO-DIMMs. The current max for nearly all laptops is 1GB of ram. The largest SO-DIMMs available are 1GB per stick. You'd have to get memory densities that were 2x what we are seeing now just to max out 32bit addressing. If this were really an issue.. needing more than 4GB of RAM in a laptop.. then I suppose the vendors would make it easier to use the real addressing size of the current processors. All the current 32bit CPUs (to the best of my knowledge) actually use 36bit physical memory addressing. If there really is a 4GB limit on today's processors, it's a lack of software/library/compiler support for the full native addressing of todays '32bit' processors.
Well have to disagree with the first premiss, many systems are implemented in such a way that the full 32 bit address range is not available even if you had memory to put into the machine. Second; I fully realize what is available memory wise at the moment but I also realize that a new generation of memory is due to come on the market. The actual instalation of the memory should not be a problem and certianly won't be in the future.
To use the exteneded addressing features of a 32 bit processor requires operating system support. It would be interesting to find out how much effort would have to be put into OS/X to support that capability, especially considering that OS/X currently manages 32 processes. I would very much like to see Apple implement extended addressing on the 32 bit side of things, sure this still limits one to 32 bit processes but that is certainly a good interim step until a viable 64 bit laptop chip come on the market.
Just because AMD is pushing 64bit processors (hot 64 bit processors) into laptops doesn't automatically mean that the laptop market needs 64bit support just yet.
Personally, I really think that you should be using a high end desktop if you need access to more than 4GB of RAM now.. or in the near future (next 2 years out). I'm not saying that there aren't people who can't use gobs of memory... but they probably need more horsepower and screen realestate than a laptop is going to provide.
Frankly the market will decide what is needed in a laptop. Currently I don't think there will be a lot of success on AMD's part in the 32 bit market. While I agree that desktops are the hardware to use, if you expect to push that hardware hard, there are some stiuations where a 64 bit machine is the wise choice. Its a matter of where you think we are technology wise, your looking at 2 years and I'm think a few months as to when this becomes feasable. Those few months are other technoligies besides the processor, at this point I'm not convinced that the 970 and its next rev. would be any more feasable in a laptop than one of AMD's chips. But that doesn't mean that the rest of the technology isn't there to solve the problem.
As far as the 970 being a better processor, I don't think there is really any question about this. The only thing about the cpu that is inferior to the current G4s would the the Altivec implementation. The inflexibility in the 970s altivec is probably more than made up for by the significantly enhanced bandwidth available.
The 970 is just a better processor. It has a higher IPC, it has gobs more bandwidth, it clocks faster... but it's design requires more software support to realize its potential. The G5 is, by most guages, a better performing machine than any G4 Mac. The dual 1.42s were giving them a run in some apps at first, but many developers have been showing significant speed gains from early optimization (Adobe excluded).
In the context of a battery ran laptop the G4 is still a good chip but aged. But with a few things addressed, as you have indicated above, the chip could be usefull for another year. On top of that a G4 like 32 bit chip form IBM could fill the role of a real G4 and provide the performance needed to keep in contemporary.
I really think that we won't see the full potential of the G5s until at least half way through next year. the fall 2004 rev of OS X will probably be heavily optimized for the G5s (10.4)
I certainly can't disagree with that. Though I do have to wonder how much effort they will put into optimizations before moving to a 64 bit OS. I could certainly see even better multiprocessing pefromance and a whole raft of libraries complied with better compilers. As it is, Apple could apparently give us quite an upgrade just buy using a better compiler, that would be rather neat.
All in all though the full potential of the G4 does not sit with the 970 or its derivatives but rather with the "980". That is with the Power 5 derived chip that is expected to come out. That will most certainly put the PowerMac into a enviable position.