More Dual PowerPC 970 Info...

MacRumors

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Original poster
Apr 12, 2001
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eWeek provides more information on the upcoming dual-core version of the PowerPC 970 due from IBM.

The original Power4 processor which was the basis of the PowerPC 970 design began as a dual core processor. According to eWeek, the additional of the second core should improve efficiency:

IBM documents suggested that hardware and software optimizations would make this processor more efficient in many computing situations than two separate processors at the same clock speed.
Similar details were previously provided by ThinkSecret.
 

GroundLoop

macrumors 68000
Mar 21, 2003
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mmmm..pseudo-4-way PowerMac...A shame that I just bought a dual 2.5 GHz. Maybe, I will upgrade to one of these when they become avaialable.
 

Diatribe

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Jan 8, 2004
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Woooh, now this sounds interesting.
Even FASTER than 2 processors running at the same clock speed? The last info said that they would be running around 3-3,5 Ghz so if you put 2 and 2 together the new ones would be running faster than a dual 4 Ghz.
This is mind boggling :D Me wants one...
I guess that also means that this will be the end of dual proc. powermacs.
 

Chaywa

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Jun 26, 2004
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Yeah,

to me this seems to spell the end of dual processor powermacs. That way apple can save money by only putting one processor in without sacrificing power and it will reduce the heat problems they have been creatively challenged to deal with. The trick will be selling these machines with one physical processor to a customer base that has come to believe that dual procs are the way to go for best performance.
 

Knox

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Jul 1, 2002
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Diatribe said:
I guess that also means that this will be the end of dual proc. powermacs.
At the bottom end I suspect you might be correct, but I wouldn't be surprised to see the top end retaining dual processors, along with the Xserve. The existing dual-core Power 4/5 machines are all multiple CPU for example, although admittedly they are a different market and price range. I think dual core is being seen as a replacement for increasing clock speed, rather than replacing multi-cpu.
 

aussiemac86

macrumors 6502
Apr 12, 2004
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the land of OZ
Yeah my dual 2.5 is on its way, but no way am i prepared to put up with the waiting for an unreleased mac again. I almost got a dual 2 in decemebr of last year, but put off until the eventual release of the rev B's..........and i am still waiting....it will all be better once it arrives
 

Diatribe

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Jan 8, 2004
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Back in the motherland
Chaywa said:
Yeah,

to me this seems to spell the end of dual processor powermacs. That way apple can save money by only putting one processor in without sacrificing power and it will reduce the heat problems they have been creatively challenged to deal with. The trick will be selling these machines with one physical processor to a customer base that has come to believe that dual procs are the way to go for best performance.
If they are really this fast it is going to be a breeze. I mean seriously, if they had a processor out by the same time next year that was about as fast as a dual 4Ghz would be right now.... how many people would be cheering and wetting their pants? :D
 

AmigoMac

macrumors 68020
Aug 5, 2003
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Does it mean ....

Powermac : Dual-Core-Dual-Processor @ 3 GHz :cool:
iMac / Powerbook : Dual-Core-Single-Processor :cool:
iBook / eMac : Actual G5 :cool:

????

Yes! Bring them up! Go IBM! Go apple! :p :p
 

AidenShaw

macrumors P6
Feb 8, 2003
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context...

Diatribe said:
Even FASTER than 2 processors running at the same clock speed?
The IBM statement most likely means "more efficient at SMP than 2 separate processors", not faster at a single-threaded task.

The reason is that a lot of "chatter" occurs between CPUs in an SMP system, for example interlocked instructions need to be coordinated and processors have to check each other's caches. (If one CPU changes a chunk of memory, if that chunk is in the other CPU's cache the cached version is no long correct.)

In standard SMP, this "snooping" occurs on the FSB (or the coherent HT link in the case of Opteron).

In a dual core chip, the snooping is within the chip itself, at full core speeds.
 

~Shard~

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Jun 4, 2003
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Although many of your are getting all excited with the thought of dual dual-core chips going into PowerMacs, has anyone every contemplated that perhaps, once these chips are ready, they won't go into dual processor machines? Perhaps the fabled 3 GHz PowerMac will not be an actual DP system, but instead have only 1 of these dual-core 970s. Sure, the effect will be the same (and from the sounds of it, it will actually be faster), but I wouldn't automatically assume that whenever these chips are ready to go, Apple will be able to simply keep their dual processor PowerMac config and slap these dual-core chips in place of the single core chips for gobs of power. I don't see this as being too likely.

As Chaywa said, this, if anything, will spell the end for the DP PowerMacs.
 

manu chao

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Jul 30, 2003
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~Shard~ said:
... this, if anything, will spell the end for the DP PowerMacs.
Will everybody please stop repeating this nonsense about this being the end of dual processor Macs.

A dual-core is nothing but two processors on one chip, there are still two processor cores in the computer. The OS and all programms will see two processors, you will even have a somewhat better performance than with a two processor computer.

If you think that the wide public and maybe yourself would perceive a dual-core Powermac as somethink less powerful than a dual-processor Powermac, you should for once accept that the opposite is the case and also rest assured that Apple marketing would try its best to correct that impression.

Naturally, everybody who said this would make it relatively easy for Apple to create a four-way computer is absolutely right.

BTW, the timestamp on the eWeek article is 26 July, three days after the Thinksecret story and three days before macrumors picked it up.
 

AidenShaw

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Feb 8, 2003
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Has the memory bus been described?

manu chao said:
The OS and all programms will see two processors, you will even have a somewhat better performance than with a two processor computer.

Note that IBM/Apple needs to double the amount of memory bandwidth per chip in order to maintain performance.

If the dual-core chips shares one memory bus (for example, if the dual-core chip (or 2) are dropped into the current G5 architecture) then the memory bandwidth *per CPU* will be halved.

That's gotta hurt.

They'll need to double the speed of the bus, double the number of busses, or double the width of the bus to maintain the current balance of memory bandwidth per CPU.
 

bathysphere

macrumors member
Oct 31, 2003
70
0
Diatribe said:
Woooh, now this sounds interesting.
Even FASTER than 2 processors running at the same clock speed? The last info said that they would be running around 3-3,5 Ghz so if you put 2 and 2 together the new ones would be running faster than a dual 4 Ghz.
This is mind boggling :D Me wants one...
I guess that also means that this will be the end of dual proc. powermacs.
that's not what they meant. they mean that a dual core 3ghz machine will run more efficiently (and a bit faster) than a conventional dual processor 3ghz machine.
a dual core 3ghz machine will not run as fast as a 6ghz, 5ghz, or 4ghz machine. it's the same logic as a regular dual processor computer, it's basically just more efficient.
 

Frobozz

macrumors 65816
Jul 24, 2002
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South Orange, NJ
EWeek said:
"This move, according to sources at IBM, is intended to expand the PowerPC's top frequency capabilities, currently at 2.5 GHz, in a dual-core configuration."
Looks like the January - March revision of the PowerMac will contain dual core 970mp's to get performance past 3GHz. The article doesn't state what GHz the chips will run at, but it does say this about the real world performance:

EWeek said:
According to Glaskowsky, customers running imaging and scientific applications developed for the Mac platform will appreciate the multicore design. "A dual-core chip is more effective than a single-core chip on problems that stress the computational resources of the chip, more than the front-side bus bandwidth. Because the 970FX has a very fast, efficient front-side bus, most Mac applications will favor the dual-core configuration."
This Glaskowsky guy is an "independant microprocessor analyst," so I wouldn't take his word as gospel... HOWEVER... this suggests an approach that will definately do two things for the Apple G5 architecture, and maybe a third:

1) Spread our heat production to a wider area, thus effectively making a much easier to maintain heat sink and dissipation profile. Though the article suggest that, since it will likely be clocked higher, it will porbably still need a water cooling heat sink.

2) Increase the relative performance of the PowerMac by making it more efficient than the dual processor design.

3) Speculation: If they don't need to use two physical chips to achieve the same scale of performance, then they might not put it into the PowerMac. This could make them cheaper to make. If they decide to keep a second chip in some high end configurations, then we actually double our current speed for a lot of things.

Personally, I think Apple will remove the second processor if they go dual core... and that's a good thing. Consider the benefits of a dual core 970 in a mobile environment, with all of the power saving features. :) Mmmmm.
 

Frobozz

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Jul 24, 2002
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AidenShaw said:
They'll need to double the speed of the bus, double the number of busses, or double the width of the bus to maintain the current balance of memory bandwidth per CPU.
So do you think they can just throw faster memory like DDR2 in the New PowerMacs, or will they have to accompany that with more bandwidth between the memory and the CPUs?
 

Frobozz

macrumors 65816
Jul 24, 2002
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South Orange, NJ
Knox said:
At the bottom end I suspect you might be correct, but I wouldn't be surprised to see the top end retaining dual processors, along with the Xserve. The existing dual-core Power 4/5 machines are all multiple CPU for example, although admittedly they are a different market and price range. I think dual core is being seen as a replacement for increasing clock speed, rather than replacing multi-cpu.
I don't know. The more I think about it, the less likely I think it will be for a dual-dual. User tasks won't benefit nearly as much from 2 dual core CPU's, on the dollar, as server applications, databases, and scientific computation would.

Honestly, they may still do it, but I'm not sure how well that would scale.
 

Phinius

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Mar 15, 2003
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Los Angeles
More lattitude for gross margins

A dual-core chip would not only be simpler and cheaper for a dual-processor computer, but it also enables Apple to move into the quad-processor server market. Dell sells a quad-processor server anywhere from about $9,000-$20,000, depending on the speed of the processor. Since Dell is the bellweather for mass market computers, Apple has a lot of potential for underpricing what Dell offers in a quad-machine, while also going after much higher gross margins.
 

Pedro Estarque

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Dec 5, 2002
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I believe that only highly threaded and very CPU hungry applications would benefit from a quad configuration. Maybe FinalCut 5 and other future Pro apps could take advantage of it and cut rendering time significantly, if they were coded properly. But I don't think Photoshop would see much improvement, as I believe the bottleneck here ( as in many other system tasks ) is memory bandwidth. I think they should make a quad Xserver for those who really need it.
I know the Mach Kernel is specially good at SMP but do you think that it can make 4 proc. talk to each other and be 350% faster then a single one on ordinary tasks ? Again, I fell that only special hard coded Apps could really benefit from such a machine. but maybe I'm wrong.
 

GFLPraxis

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Mar 17, 2004
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Pedro Estarque said:
I believe that only highly threaded and very CPU hungry applications would benefit from a quad configuration. Maybe FinalCut 5 and other future Pro apps could take advantage of it and cut rendering time significantly, if they were coded properly. But I don't think Photoshop would see much improvement, as I believe the bottleneck here ( as in many other system tasks ) is memory bandwidth. I think they should make a quad Xserver for those who really need it.
I know the Mach Kernel is specially good at SMP but do you think that it can make 4 proc. talk to each other and be 350% faster then a single one on ordinary tasks ? Again, I fell that only special hard coded Apps could really benefit from such a machine. but maybe I'm wrong.
I disagree.
If they make Tiger highly threaded...
Imagine. You run Photoshop CS, Final Cut Pro 4, and Maya3D all at the same time.
Since Tiger is threaded, it allocates the programs-
Processor 1: OS X core system processes
Processor 2: Photoshop CS
Processor 3: Final Cut Pro 4
Processor 4: Maya3D

Even if Photoshop, Final Cut Pro, and Maya WEREN'T multithreaded, Tiger itself (being a multithreaded OS) would give each program it's own processor.

Result? Speed boost, baby!
 

The Red Wolf

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Apr 13, 2004
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Occi Dens Pacifica
Architecture

I seriously doubt Apple would have gone to such lengths to water cool the dual 2.5 without refining the technology for future use. Would a dual core single chip be as hot as two 2.5s? Maybe. But more efficient and lower wattage don't speak to that. What if a refined water cooling system and dual core twin G5s make it into the high end G5? Reasonable?

Single chip, dual core Low end G5 Tower.
Single chip, dual core Mid range G5 Tower.
Twin chip, dual core - water cooled, High end G5 Tower.

Thoughts?
 

nuckinfutz

macrumors 603
Jul 3, 2002
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People this is sweet

Like the poster above said. 970MP processors will give Apple much more lattitude in system design.

No this doesn't mean it's the end of 2 socket Powermacs. While it's true they can now do SMP with 1 CPU socket I have no doubt that Apple will have a high end configuration with 2 970MP. They won't have the luxury of not doing this because you better believe the dual core Opterons will be working in 2 socket motherboards and possible 4 socket.

As for the FSB we have to remember that the Powermac FSB is largely marketing. I'm not saying this because it's not real but we must look as the real bottleneck. The 1250mhz FSB can support 10GBps (5GBps up/down) of bandwidth. There is no way the dual 2.5 with its PC3200 memory is even getting close. Both CPU must share the total DDR bandwidth amount of 6.4GBps despite the fact that the bus can handle %50+ more bandwidth.

So even if we put both processors ondie and have them share a 1Ghz FSB we won't see a hit usually because not many applications stress the FSB. I'm very willing to see the L2 cache quadruple and the chip to chip communication speed increase with lower latency. That will really help some applications.

I expect Apple will have 2 socket 970MP systems provided IBM yields are sufficient. Don't expect them to be cheap however. I wouldnt' be suprised to see a Quad core system run $3999. This would limit the demand to mainly professionals and ensure that profitability for Apple. I do know there are a lot of people who'd be interested though. 3D animators, Video production pros, audio production, Scientific reseachers etc

Remember these systems aren't shipping until as late as mid 2005. They would not come without OSX 10.4 Tiger. Also remember that Tiger has synced with BSD 5.x and now has the fine grain locking for SMP systems and the kernel now can differentiate between "physical" and "logical" processors. Had Apple not planned to go beyond 2 cpu/cores then these functions in Tiger would not be needed.

As for threaded apps people need to realize why the current SMP systems multitask so well. Remember you will see a speed increase whether you are running one app with multiple threads or multiple single threaded apps. Either way you will derive a benefit from SMP.
 

nuckinfutz

macrumors 603
Jul 3, 2002
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The Red Wolf.

Exactly. I'm suprised at how many writers have commented about how hot the Dual 2.5Ghz chips are without having any empirical evidence regarding the heat max on this cpu. They are basically assuming that the chips are ungodly hot because of the LC system. Well I prefer to think of it as over engineering for the future.

Now that the 970MP system is potentially coming we can see why the liquid colling system will be necessary. Having both cores on the same die gives a wider area to cool which should help. Plus from the eWeek article we see there are enhancements to Powertune as well that will throttle the cores in tandem if things get a bit too hot.

Once 2.5Ghz owners get their computers sometime next week we'll have a better idea on how effective the LC system is and if it's suitable for cooling as many as 4 cores.
 

Pedro Estarque

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Dec 5, 2002
131
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GFLPraxis said:
Processor 1: OS X core system processes
Processor 2: Photoshop CS
Processor 3: Final Cut Pro 4
Processor 4: Maya3D
Result? Speed boost, baby!
Do you really run all this Apps together every day ? Wouldn't you prefer to run one of then but much much faster instead of 3 of them at you current speed?
If I'm editing some movie I won't be doing heavy Photoshoping. Maybe open one file and make some light changes. I would much rather see the end of the progress bar then being able run more at once without sacrificing current speed.
 

GFLPraxis

macrumors 604
Mar 17, 2004
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Pedro Estarque said:
Do you really run all this Apps together every day ? Wouldn't you prefer to run one of then but much much faster instead of 3 of them at you current speed?
If I'm editing some movie I won't be doing heavy Photoshoping. Maybe open one file and make some light changes. I would much rather see the end of the progress bar then being able run more at once without sacrificing current speed.
I'm just making an example ;)

A better example would be, Maya 3D, Motion, and Final Cut. Or maybe SoundStudio.

What I'm saying is, even if you have a program that isn't multithreaded, the processor will stick each program on its own processor, letting you run four programs each at the speed of only one on a single processor. Whoo!
 
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