1. because the price would jump accordingly; assuming 1 processor costs $400 (random figure), 2 would cost $800, 3 would cost $1200 and 4 would cost $1600. would you be willing to pay $1600 dollars just for the processors? they would still need to add other things that make up a computer; a hard drive, an optical drive, mouse, keyboard, fans, power supply unit, etc. etc. you know the drill.
2. how do you think they would be able to fit 4 processors in the same box and still keep it cool and quiet (as opposed to noisy)? how many fans would that require (think added cost), how much noise would that create?
3. who needs 4 processors in one machine? excluding star wars guys.
4. how would they sell machines with 4 processors if there is absolutely no need for them? at least, at the present moment. who would pay, say, $6000 + the display for one computer?
If dual processor is better than single why they dont make tri or quat processor?
Sorry for stupid question
Not a stupid question by any means. The more processors you have the higher the costs as Gene Clean stated before but you also raise the complexity of the motherboard as well increasing costs there. I think we will have more cpu power once Multi Core CPUs hit. This is literally two seperate CPU sitting on the same piece of silicon. Add two of those to a computer and you have 4 distinct processing units but you have only taken the space for two.
I think there is four reasons we've not seen quad processor macs (yet):
1) North-bridge complexity. The complexity for controlling and distributing memory bandwidth for four processor chips is huge and requires a lot of research and development. Not to mention that the G4 processor has to share its FSB bandwidth with the other processor(s). The performance gained adding more processors Is Not Worth It?.
2) Heat/space. The extra processors would generate a lot of heat and require a lot of space for wiring and controlling on the motherboard, not to mention huge blocks of aluminum ribs and large fans. It would require a enclosure redesign for a limited set of computers with a limited set of buyers.
4) Few processors have generally been fast enough. Due to the single-threaded nature of most programs, more processors would generally not result in a performance increase significant enough to justify the cost.
However, we will see macs with four processor cores in the (near) future. As single-threaded performance evolution will slow down a lot, processor manufacturers will have to add cores to yield significant performance increases. The result is that when every processor manufacturer create multi-core processor, it will be feasible for developers to create multi-threaded code to take advantage of these new cores. This has been, and still is some of a "chicken and egg" problem. If there are few processors capable to take advantage of multi-threaded code, why multi-thread code? If there is little multi-threaded code out there, why bother implementing more cores on the chip?
This has been, and still is some of a "chicken and egg" problem. If there are few processors capable to take advantage of multi-threaded code, why multi-thread code? If there is little multi-threaded code out there, why bother implementing more cores on the chip?
imo, the chicken is here, in the form of dual proc powermacs. ie: plenty of incentive to multithread media apps (imaging, audio, video) with existing hardware.
and we already know multicore chips are on deck for 2005/2006, so clearly the incentive for multithreaded software will grow more enticing.
that said, writing useful multithreaded software is more difficult than single threaded logic. so there's some training to be done among the existing programming world.
but threaded architecture design/coding will no doubt become a required course (if not already) at all university CS depts, so the number of quality threaded coders should increase as the chips roll out.
Yes, the chicken has sort of been here since 2000, when the dual processor PowerMacs entered the market and stayed there. The egg begun to grow noticeably when OS X was released, at least for the mac side. Many apps, which exist on both the Mac and Windows still remain single-threaded, with good reason. Single-threaded performance has scaled much more rapidly on the x86 side (iow. it has been "good enough"), and it hasn't been much of an incentive to multi-thread the code for either platform (and certainly not for the minority the mac represents).
Actually they do make quad processor systems. Of course they may mean sombody besides Apple at the moment.
The question is not stupid. There are many issues that come into play when designing such machines. Some times the result is that mor that 2X SMP doesn't pay off. This was the case with the G4 which often suffers from front side bus (FSB) issues when runned in multi processor systems. Often the SMP performance of G4 systems suffered greatly depending on the load applied.
The 970 series, from IBM, does much better under most multiprocessing work loads likely to be seen on most Macs. I do expect that we will see quad systems from Apple soon to take advantage of this performance possibility.
Implementation can be costly as other have pointed out. Technology though moves forward, dual core processors effectively reduce the implementation issues dramatically. Off chip, new bus technologies extend the usefullness of motherboard technologies so that quad board can be implemented without dual cores.
As to SMP or other multiprocesssing technologies I think we are at a technology crossroads today. In a year or two finding systems that aren't multiprocessor will be very difficult.
Dave
Quote:
Originally posted by irene
If dual processor is better than single why they dont make tri or quat processor?
A quad processor Power PC Mac system exists already. I don't buy the "complexity" and "research" excuses.
I'm not either. I'm buying the "heat issues", "overpriced" and "what am I gonna do with 4 G5s in my computer" excuses. The quad proc from Daystar didn't have the same issues : the PPC604 ran quite cool, and price and target market were not issues since Daystar R&D department was funded by Apple to boost their assets in the area of multi-processor mother board design. Anyway, Daystar's quads were an exercise of style more than a really competitive product, since it used master-slave design and eventually hardly boosted anything...
If dual processor is better than single why they dont make tri or quat processor?
Sorry for stupid question
As far as I can remember there are patent and licensing problems for systems with more than 2 processors. During the times of Mac clones one of the clone manufacturers applied for the patents and rights to exclusively make quad- or more processor machines. Since SJ kicked them out of businesss they certainly will not sell their rights.
You do realize that the "overpriced" issue is connected with the "complexity" and "research" issue?
I don't agree... The price of a quad config is high merely because you actually have to buy the 4 CPUs! Design costs are not the main obstacle. So actually, that's a "4 oranges cost more than 1 orange" issue, which has nothing to do with research or complexity.
Anyway I do agree on the fact that heat issues are connected with complexity and research issues. But they are not the main problems IMO (I'm quite sure that a well made watercooling system would be able to cool everything down).
Seems to me that 4 -processors have to cost more than 2 processors and a board to hold 4 processors has to cost more than a board that holds 2 processors, Therefore....
Check the prices for PC motherboards -- a 4-way board might cost over $1500 while a 2-way board similar to the PMac's could be had for $300 or so. So the "design cost" does not increase linearlly with the number of CPUs.
There's also the question why. 2-way machines make sense because that's what workstations ship with. However, I don't see the application requirements for 4-way. Maybe if people wanted to run Oracle on a server box.
Overall, 4-16 CPU systems have been declining in marketshare for years.
Check the prices for PC motherboards -- a 4-way board might cost over $1500 while a 2-way board similar to the PMac's could be had for $300 or so. So the "design cost" does not increase linearlly with the number of CPUs.
there's probably also an economy of scale in the price difference. ie: far more 2-slot boards sold than 4-slot.
but there's no doubt on the issue of complexity. memory sharing alone is a major issue.
Sometimes MP hurts performances with single threaded application.
A programmer who presented a new medical software during our annual congress explained me that he had problems with a dual G5 as a server with a particular soft. The problems disappeared when they exchanded it for a single.
I must add that he has a very good knowlegde of the macs, and that his demo was made on a mac (his soft was build upon file maker pro).
He said others interestings things, that I will discuss on GD.
Unless you are able to prove that the 4 CPUs are so costly as you seem to think, I think we have to agree to disagree. :-)
I think the motherboard complexity and research cost to create it is very significant.
Since I'm involved in SoC design, I know how much a CPU costs. Sorry! Anyway, 4 G5s are awesomely costly, and the mobo research cost is "marginal" compared to the 4 G5s. I agree on the fact that when building quads with low-power chips, the CPU/mobo price ratio is not the same anymore, though...
The fact is that quad is non-sense for Apple since dual-cores are likely to be released "soon". Dual dual-core = quad!
Comments
2. how do you think they would be able to fit 4 processors in the same box and still keep it cool and quiet (as opposed to noisy)? how many fans would that require (think added cost), how much noise would that create?
3. who needs 4 processors in one machine? excluding star wars guys.
4. how would they sell machines with 4 processors if there is absolutely no need for them? at least, at the present moment. who would pay, say, $6000 + the display for one computer?
5. etc., etc.
Originally posted by irene
If dual processor is better than single why they dont make tri or quat processor?
Sorry for stupid question
Not a stupid question by any means. The more processors you have the higher the costs as Gene Clean stated before but you also raise the complexity of the motherboard as well increasing costs there. I think we will have more cpu power once Multi Core CPUs hit. This is literally two seperate CPU sitting on the same piece of silicon. Add two of those to a computer and you have 4 distinct processing units but you have only taken the space for two.
We should see this perhaps as early as late 2005
1) North-bridge complexity. The complexity for controlling and distributing memory bandwidth for four processor chips is huge and requires a lot of research and development. Not to mention that the G4 processor has to share its FSB bandwidth with the other processor(s). The performance gained adding more processors Is Not Worth It?.
2) Heat/space. The extra processors would generate a lot of heat and require a lot of space for wiring and controlling on the motherboard, not to mention huge blocks of aluminum ribs and large fans. It would require a enclosure redesign for a limited set of computers with a limited set of buyers.
3) Cost. Processors themselves cost, companion chip development costs, cooling solutions cost, huge enclosures cost.
4) Few processors have generally been fast enough. Due to the single-threaded nature of most programs, more processors would generally not result in a performance increase significant enough to justify the cost.
However, we will see macs with four processor cores in the (near) future. As single-threaded performance evolution will slow down a lot, processor manufacturers will have to add cores to yield significant performance increases. The result is that when every processor manufacturer create multi-core processor, it will be feasible for developers to create multi-threaded code to take advantage of these new cores. This has been, and still is some of a "chicken and egg" problem. If there are few processors capable to take advantage of multi-threaded code, why multi-thread code? If there is little multi-threaded code out there, why bother implementing more cores on the chip?
Originally posted by Zapchud
This has been, and still is some of a "chicken and egg" problem. If there are few processors capable to take advantage of multi-threaded code, why multi-thread code? If there is little multi-threaded code out there, why bother implementing more cores on the chip?
imo, the chicken is here, in the form of dual proc powermacs. ie: plenty of incentive to multithread media apps (imaging, audio, video) with existing hardware.
and we already know multicore chips are on deck for 2005/2006, so clearly the incentive for multithreaded software will grow more enticing.
that said, writing useful multithreaded software is more difficult than single threaded logic. so there's some training to be done among the existing programming world.
but threaded architecture design/coding will no doubt become a required course (if not already) at all university CS depts, so the number of quality threaded coders should increase as the chips roll out.
Originally posted by tonton
A quad processor Power PC Mac system exists already. I don't buy the "complexity" and "research" excuses.
are you referring to the daystar genesis from the mid-90s? as i recall, they cost over $6500. more than double the dual 604s of the same timeframe.
Actually they do make quad processor systems. Of course they may mean sombody besides Apple at the moment.
The question is not stupid. There are many issues that come into play when designing such machines. Some times the result is that mor that 2X SMP doesn't pay off. This was the case with the G4 which often suffers from front side bus (FSB) issues when runned in multi processor systems. Often the SMP performance of G4 systems suffered greatly depending on the load applied.
The 970 series, from IBM, does much better under most multiprocessing work loads likely to be seen on most Macs. I do expect that we will see quad systems from Apple soon to take advantage of this performance possibility.
Implementation can be costly as other have pointed out. Technology though moves forward, dual core processors effectively reduce the implementation issues dramatically. Off chip, new bus technologies extend the usefullness of motherboard technologies so that quad board can be implemented without dual cores.
As to SMP or other multiprocesssing technologies I think we are at a technology crossroads today. In a year or two finding systems that aren't multiprocessor will be very difficult.
Dave
Originally posted by irene
If dual processor is better than single why they dont make tri or quat processor?
Sorry for stupid question
Originally posted by tonton
A quad processor Power PC Mac system exists already. I don't buy the "complexity" and "research" excuses.
So ... when are you placing your order?
Originally posted by tonton
A quad processor Power PC Mac system exists already. I don't buy the "complexity" and "research" excuses.
I'm not either. I'm buying the "heat issues", "overpriced" and "what am I gonna do with 4 G5s in my computer" excuses. The quad proc from Daystar didn't have the same issues : the PPC604 ran quite cool, and price and target market were not issues since Daystar R&D department was funded by Apple to boost their assets in the area of multi-processor mother board design. Anyway, Daystar's quads were an exercise of style more than a really competitive product, since it used master-slave design and eventually hardly boosted anything...
Originally posted by irene
If dual processor is better than single why they dont make tri or quat processor?
Sorry for stupid question
As far as I can remember there are patent and licensing problems for systems with more than 2 processors. During the times of Mac clones one of the clone manufacturers applied for the patents and rights to exclusively make quad- or more processor machines. Since SJ kicked them out of businesss they certainly will not sell their rights.
Originally posted by The One to Rescue
I'm not either. I'm buying the "heat issues", "overpriced"
You do realize that the "overpriced" issue is connected with the "complexity" and "research" issue?
Originally posted by Zapchud
You do realize that the "overpriced" issue is connected with the "complexity" and "research" issue?
I don't agree... The price of a quad config is high merely because you actually have to buy the 4 CPUs! Design costs are not the main obstacle. So actually, that's a "4 oranges cost more than 1 orange" issue, which has nothing to do with research or complexity.
Anyway I do agree on the fact that heat issues are connected with complexity and research issues. But they are not the main problems IMO (I'm quite sure that a well made watercooling system would be able to cool everything down).
In the meantime, people that need lots of proc power buy themselves racks of Xserves and cluster them.
No real need to make a quad or octa processor tower.
Originally posted by The One to Rescue
I don't agree... The price of a quad config is high merely because you actually have to buy the 4 CPUs! Design costs are not the main obstacle.
Unless you are able to prove that the 4 CPUs are so costly as you seem to think, I think we have to agree to disagree. :-)
I think the motherboard complexity and research cost to create it is very significant.
There's also the question why. 2-way machines make sense because that's what workstations ship with. However, I don't see the application requirements for 4-way. Maybe if people wanted to run Oracle on a server box.
Overall, 4-16 CPU systems have been declining in marketshare for years.
Originally posted by IntlHarvester
Check the prices for PC motherboards -- a 4-way board might cost over $1500 while a 2-way board similar to the PMac's could be had for $300 or so. So the "design cost" does not increase linearlly with the number of CPUs.
there's probably also an economy of scale in the price difference. ie: far more 2-slot boards sold than 4-slot.
but there's no doubt on the issue of complexity. memory sharing alone is a major issue.
A programmer who presented a new medical software during our annual congress explained me that he had problems with a dual G5 as a server with a particular soft. The problems disappeared when they exchanded it for a single.
I must add that he has a very good knowlegde of the macs, and that his demo was made on a mac (his soft was build upon file maker pro).
He said others interestings things, that I will discuss on GD.
Originally posted by Zapchud
Unless you are able to prove that the 4 CPUs are so costly as you seem to think, I think we have to agree to disagree. :-)
I think the motherboard complexity and research cost to create it is very significant.
Since I'm involved in SoC design, I know how much a CPU costs. Sorry! Anyway, 4 G5s are awesomely costly, and the mobo research cost is "marginal" compared to the 4 G5s. I agree on the fact that when building quads with low-power chips, the CPU/mobo price ratio is not the same anymore, though...
The fact is that quad is non-sense for Apple since dual-cores are likely to be released "soon". Dual dual-core = quad!
Originally posted by The One to Rescue
Since I'm involved in SoC design, I know how much a CPU costs.
Great. Do you have any numbers?
Sorry!
Why?