Quad Processor Mac

HA

 

Double HA

 

Motorola made the decision to downgrade the cache coherency in the 7400 from the Quad capable standard (Apple wasn't using it) to something more suitable to singles/duals.

The MERSI/MESI differences ...

The 604s had it and the 7400 had the more capable cache coherency, the rest of the G4s basically don't (can't remember exactly which 74xx unit killed it either, but it's l years back).

 

I'd say it could happen, but not in anything resembling a consumer machine--if the power consumption and heatsinks on the current duals are any indication, it'd take a big, beefy, noisy box to handle four G5s. I'd say it might still happen for a server or workstation, but I wouldn't bet on it yet.

Just for reference, based on my quick testing with my "measly" dual G5, a quad version would draw a HUGE amount of power and have big ol' heatsinks and fans to deal with the heat generated. My old G4 dual drew in the range of 100W, give or take. My G5 draws 170W idling, and can easily go up over 325W if you push it. By extrapolation, a quad version would need at minimum 500W of power, likely a lot more (I don't even have any addon cards, and the computer isn't powering a monitor, either--the Cinema Display via ADC has got to suck some serious juice), and cooling to match.

That adds up to a major power supply, a lot of cooling, a whole lot of heatsink on those G5s (they're probably a third of the volume of the current huge case) or a much louder set of fans/liquid cooling, and one hefty mother of a computer.

Not that it can't be done, but not in the current tower case without at the very least making a massive amount of noise, and I'd guess realistically you'd need something much bigger.

 

"mini-AC" huh. you're clearly adept at engineering. it's called a heat pump, and if you knew that much, you'd know why it isn't going to happen. no offense. even if they got past the magnetic and electrical noise that the pump itself would create, which would be quite a chore, they'd have to deal with the potential problem of one/more processors getting too cold and cracking... the electical draw would be phoenomenal, probably enough to warrant a 220 circuit (and who wants to unplug their Mac to run the dryer?), the heat that the pump moved into the room would be enough to make a cooling system for the room necessary (heat doesn't just disappear)...

starting to see why apple can't simply "invest in a mini A/C"?

liquid pipe cooling, or submerged liquid cooling, would be the only options. and frankly i don't think they would draw nearly enough heat away from the processors.

pnw

 

it'd probably be over kill for a powermac, but, i wouldn't rule out future xserve's

and if they were to make a dual core G5, a dual G5 would essentially be quad, without necesarily all of the problems of 4 cpu's.... still doubtful

 

Couldn't you get 2 dual G5 Powermacs(or 2 Dual G5 xServes when they come out), cluster them together, and get the same affect?

 

There's a company called Asetek that have a product called the VapoChill. It basically is like a A/C or Refrigerator. Here is a review of it: http://www.hardocp.com/article.html?art=NDAw

 

Well, since IBM joint created the cell technology, something along those lines wouldnt be that farfetched. Its probably never going to happen, and if it did its time is far from now. The cell technology is in its baby stages.

http://www-1.ibm.com/mediumbusiness/venture_development/content/featurearticle.jsp?id=8649

 

can you imagine the size of a Quad proc, tower? and the amout of heat it would produce.

 

Probably as much heat as a dual Itanic.

 

The Quad G4 would probably still cost more

 

Doesn't AMD have an Opteron that's Quad capable? Talk about hot! My Duron gets a little toasty, but you could use one of those as a heater.

Probably still cooler that a P4 EE, or 100W + Prescott. Ouch. Here's hoping the next G5s aren't that hot.

Edit: And no, 4 G4s probably still cost way less than 1 Itanic. Unless you meant G5, but even then... The Opteron isn't as bad, but those Dual capable Motherboards aren't exactly cheap.

Hey, how did Exlaxxboy get banned?

 

The last quad CPU Mac OS machine was only $10,000 in 1997/8

 

Pee-Ceers don't care...

"Doesn't AMD have an Opteron that's Quad capable? Talk about hot! My Duron gets a little toasty, but you could use one of those as a heater."


IMO, PC Users do not care about how hot/noisy a machine is... Otherwise there wouldn't be those 3" thick/ 3 Kg laptops.

At work, I have 2 Xeon dual processor and don't let me listen my tunes.

 

XnavxeMiyyep:

Only on certain software. You'd pretty much need problems that could be solved separately.

Exlaxxboy:

The heat has to go somewhere. You can move it around but somehow it has to leave the system.

G5orbust:

Multiple processor cores per die has nothing to do with the cell technology. Most companies are preparing multi-core chips, including x86 chips that will compete directly with the G5's sucessors. I bet we'll see a multi-core Mac chip sooner or later.

Sun Baked:

Probably more, assuming your talking about G5's. Last time I looked at Intel's page, even the 1.5ghz 6MB L3 Itanium2 is somewhere in the 100W max output range. As you know, a 1.8ghz G5 "typically" produces just under half that, so it would not be hard to imagine 4 2ghz G5's producing a maximum total of more than 200W.

solvs:

Yeah, they scale to 8-way and there are 4-way systems on the market now. Opterons are probably not much hotter than G5's at the same clockspeed, although the exact figures for each are not known. People have had excellent luck with clock-throttling A64's running pretty cool, for example

http://www.aceshardware.com/forum?read=105050725

AmigoMac:

I know lots of PC users who care a lot about it. There are entire specialty shops on the web for quiet PC components, there are specialty cases, acoustic padding, heatsinks, fans and power supplies. When PC users outnumber Mac users 19 to 1 you can bet there are a lot of different types of PC users that have plenty of market presence. Painting PC users with such a broad brush reflects poorly on you. Check this link out:

http://store.yahoo.com/siliconacoustics/index.html

 

I think we are thinking of two different things. I misunderstood what he said when I quoted him, so you are correct. But, on the other hand, use of the cell technology wouldnt be such a bad idea either

 

dual core is feasible but the issue is connectivity and the relationship each of the 'sub cores' would have with relevant electronics such as cache and register pipes. Even MIPS have avoided the idea of multi core systems in place of multi CPU node boards because of the (im assuming) unnecessary sophistication required to manage interleaving resources and basic chip manufacture attrition.

There is all this talk about heat and power consumption!! Crap. Lets set some ground rules...

1) if you have the requirement for mass MP h/w environments then power shouldn't be an issue. If it is, get the hell out of your living room and hire an office or a factory.

2)Heat? its a simple physics thing... POINT A FAN AT IT YOU IDIOT. heat, unlike the flow of electric signal, is NOT directly registrable by electronics, therefore the cooling of it is (to borrow an expression) 'off-line' to the actual running of it. Hence, there is no finite answers, no actual figures and now real rules other than once it gets to hot it burns and if it gets too cold it cracks.

The question that seems to be missing in all of this is WHY do you need more than two CPU's?
{{And for all you PC flunkies, MP systems under Motorola or IBM systems are more than capable, they are products and piss on any Intel or AMD calculators from a lofty height. }}
If your reasons are because of normal work flow you may have a wait on your hands because it would be necessary for apple to recompile the mach kernel (either the 32 or 64 bit versions of BSD) to make it capable of more than two CPU's. This is fairly easy but getting the now realGUI like osX to play the game is a task i wouldn't put on my enemies.

G5? you mean POWER4 don't you? why don't you have a look at the genesis for the G5 and see how it handles MPing...

The issues are simple:

1) OS capability.
2) Need for doing so.

In both cases it comes down to the AMOUNT of people who require the need for mass parallel processing and their ability to pay for it. YES it is more than possible and in fact is done regularly in a variety of ways but due to the relatively small number of real reasons to do it there is a natural lack of OS support and the hence the applications to utilize it.

The exception to this is Beowulf style distributed network clustering. OR go and have a look at SGI archives on systems like the Origin 2000 and you'll learn a few things about the realities behind the NEED for MP environments.

 

I don't like that ElaxxBoy is being berated

I find it to be a perfectly valid question

after all - OS X was designed to handle 4 processors, if need be

and it also has 9 freaking fans ---- I'm sure that could accomodate 2 more processors

 

I'm noticing the over-use of the word 'Probably' in this thread.

You guys are probably all electrical engineers too, right?

 

Probably...

Either that or electrical imagineers.

The hopes for a Quad G4 Mac died when Motorola went from MERSI to MESI cache coherency. Though with all the cache problems the G4 had through the 7457, it would have been a PIA.

A 400MHz Quad PowerMac G4 just doesn't quite sound as useful as a DP 1.42GHz PowerMac.

The Quad G5 using the original 970, would have been heat/power -- seems the original 2GHz G5 was as bad as the Itanic with around a 100W maximum for each CPU. Plus each CPU needs x pins for support on the System Controller. So the system controller gets quite a bit bigger, hotter, and more power hungry.

But we'll see when and if people start offering Quad PPC970s.

 

ZetaPotential:

A Quad G5 would have a superior through more expensive layout when compared to a quad Xeon, since the G5 would have 4 FSB's vs just one. (The Xeon would, however, have the advantage of L3 caches.) The quad G5 would have an inferior and more expensive layout when compared to a quad Opteron, since the Opteron has on-die memory controllers (4 128-bit channels for a quad) and direct chip-to-chip HT links in addition to larger caches which reduce the need to use those memory resources. The cost savings for the Opteron comes in not needing any monolithic chipset with 4 FSB's and 256 to 512 bits of memory interface (actually wider including ECC).