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Dual Core PowerPC 970s

I agree...

Single threaded apps will not benifit from a dual core...
Then again they also dont benifit from a dual processor either...

Fortunately for me, The only interest I have in the ppc is for use in clusters..
So the dual core CPU's would bring a benifit to me ..... Higher CPU density per rack.

Also a Dual (Dual)Core xserve will cost me less for my low latency interconnect too... since I would only have to buy 1/2 as many cards and Switch ports.
 
edgar_is_good said:
Sheesh, and everyone's missing the obvious possibility that he was originally talking about an English soccer/football team named "news", in which case it would be "if these news are correct, they are the best team in Europe"
Click to expand...

What? That makes no sense at all! "If these Arsenal are correct .." makes no sense, why would a non-existent team called "news" be?

It should be "If this news is correct ... " or "If these rumours are correct ...". Maybe "If these news articles are correct".

And English, even in the UK, has moved on a lot since Shakespeare. "If this news be correct" is bad grammar. You might as well say "If incorrect this news be" or something else equally silly.
 
macsrus said:
Also a Dual (Dual)Core xserve will cost me less for my low latency interconnect too... since I would only have to buy 1/2 as many cards and Switch ports.
Click to expand...

Agreed. A dual-dual JS20 would kick b#tt for some applications - and you'd have 168 CPUs per rack (or 336 logical CPUs). The mezzanine IB or Myrinet card would give you the interconnect at a good price too.

Probably wouldn't do that well on LINPACK (Top500) though - unless the current FSB is replaced with something that scales to twice to four times the bandwidth.
 
Hattig said:
And English, even in the UK, has moved on a lot since Shakespeare. "If this news be correct" is bad grammar. You might as well say "If incorrect this news be" or something else equally silly.
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I'm just as guilty as anyone for posting on the grammar thing, but it's getting kinda old, no?

"If this news be correct" is not bad grammar - as someone pointed out earlier it's an example of the present subjunctive being used (correctly) in place of the indicative - but it is an extremely archaic usage, and is one that you are unlikely to encounter these days.

English is full of similar examples: as someone once said, jokingly: "The use of a preposition to end a sentence is an abomination up with which I shall not put!" This is grammatically correct, but, one hopes, won't ever be said!

How 'bout we all call it a day on the grammar front?
 
jouster said:
I'm just as guilty as anyone for posting on the grammar thing, but it's getting kinda old, no?

How 'bout we all call it a day on the grammar front?
Click to expand...

I was just working my way through the thread. It reminded me of a story recently on Slashdot that argued that Mac users were better with English grammar than non-Mac users, and I was thinking how much this thread was trying to disprove that theory.

Anyway, my guess for the PowerMac 2005:

1) Dual 3GHz 970DP, PCIe x16, DDR2-800. Either 2x1.5 GHz bus, or 3x1GHz.
2) Dual 2.6GHz 970DP, PCIe x16, DDR2-666. Either 2x1.3 GHz bus, or 3x900MHz (2.7Ghz).
3) Dual 2.2GHz 970DP, PCIe x16, DDR2-666. 2x1.1GHz bus, or 3x800MHz (2.4GHz).
 
SMP benefits all processes

macsrus said:
Single threaded apps will not benifit from a dual core...
Then again they also dont benifit from a dual processor either...
Click to expand...
Sure they do.

OK, in theory, in a vacuum, a single threaded app won't benefit from SMP.

But that single threaded app doesn't run in a vacuum, especially on a mac.

It runs alongside the kernel, the display manger, whatever servers are going on, virtual memory, etc.

A smart kernel gives any thread the least-used CPU. A really smart kernel would give your CPU-intensive single-threaded app to one core, and keep system stuff on another. In a dual/dual setup it would have VM on one, display on another, your app on a third and servers on a fouth.

You see this on both macs and PC/linux machines - SMP machines are more responsive overall, even with single-threadded apps and at the same clock.

Yes there is a hit for context switching but it's noise in the system in the final analysis.

(note to the nut who goes on about me personifying task schedulers: it's a literary device, get over it)
 
but aren't we in a vacuum?

ClimbingTheLog said:
You see this on both macs and PC/linux machines - SMP machines are more responsive overall, even with single-threadded apps and at the same clock.
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Responsiveness can be a misleading metric.

The dual might feel more responsive while your single-threaded app is running, but you might find an insignificant speedup in the amount of work that gets done. The system doesn't seem to slow down while doing the 30 CPU minute app, but the app takes exactly 30 minutes rather than 30 minutes and 20 seconds.

Clearly, if you often have more than one computing thread that needs a lot of CPU (whether it's multiple single-threaded apps or a multi-threaded app), the dual will be better.

If you have a single thread, the 4GHz single will tromp the 3GHz dual.

I'm not trying to simply argue, I just want people to realize that a dual is almost never twice as fast as a single. YMMV. Thanks for listening....
 
clarity

macsrus said:
I agree...

Single threaded apps will not benifit from a dual core...
Then again they also dont benifit from a dual processor either...

Fortunately for me, The only interest I have in the ppc is for use in clusters..
So the dual core CPU's would bring a benifit to me ..... Higher CPU density per rack.

Also a Dual (Dual)Core xserve will cost me less for my low latency interconnect too... since I would only have to buy 1/2 as many cards and Switch ports.
Click to expand...


OK I thought the whole point of ANY version of OS X and PowerMacs going to Dual Processors was the FACT that the OS will be able to distribute threads onto more than one processer. IS this a fact or is it a myth??? Please someone clarify. That said if its a FACT, then why can't single threaded apps benifit from Dual Processor, or even from Dual Core cpu's.
 
bonk said:
did no one laugh at my dual dual dual dual comment?



sigh
Click to expand...

Evidently one person did. You. :cool:

And just a little piece of advice - it makes it look even worse when you have to quote your own post to draw attention to it. :p :cool:
 
Prom1 said:
OK I thought the whole point of ANY version of OS X and PowerMacs going to Dual Processors was the FACT that the OS will be able to distribute threads onto more than one processer. IS this a fact or is it a myth??? Please someone clarify. That said if its a FACT, then why can't single threaded apps benifit from Dual Processor, or even from Dual Core cpu's.
Click to expand...

Let me try to clarify this....

Programs by design can be either single or multithreaded....
Most applications are single threaded...
An operating system controls when and where an application's thread/threads are alotted CPU time.

Multithreaded apps can have their threads spread over multiple CPUs if a system has more than one CPU...
Single threaded apps do not benifit from multiple cpus.....
 
AidenShaw said:
Responsiveness can be a misleading metric.

The dual might feel more responsive while your single-threaded app is running, but you might find an insignificant speedup in the amount of work that gets done. The system doesn't seem to slow down while doing the 30 CPU minute app, but the app takes exactly 30 minutes rather than 30 minutes and 20 seconds.

Clearly, if you often have more than one computing thread that needs a lot of CPU (whether it's multiple single-threaded apps or a multi-threaded app), the dual will be better.

If you have a single thread, the 4GHz single will tromp the 3GHz dual.

I'm not trying to simply argue, I just want people to realize that a dual is almost never twice as fast as a single. YMMV. Thanks for listening....
Click to expand...



True True
 
Earth Shaking Announcement right here...

macsrus said:
Let me try to clarify this....

Programs by design can be either single or multithreaded....
Most applications are single threaded...
An operating system controls when and where an application's thread/threads are alotted CPU time.

Multithreaded apps can have their threads spread over multiple CPUs if a system has more than one CPU...
Single threaded apps do not benifit from multiple cpus.....
Click to expand...

Are you ready for this:
Most Apps are Multi-Threaded!
Go to Applications/Utilities/ and start Activity Monitor
Press AppleKey-1 which equals Show Activity Monitor

Now take a look at the currently running processes on your machine.
It's actually HARD to find a process running just 1 thread!

Finder uses 1
Palm Desktop Background 1
System Events 1

But, on the other hand:
My personal favorite: Borland JBuilder: 14
Safari: 5
Dreamweaver: 5
iTunes: 9 -- just playing a song in a play list!
Word: 5 -- just an open document
Powerpoint: -- 1 new doc open
Excel: 4 -- 1 new doc open

The days of running JUST StarRaiders on our Atari800's are over.

;)
 
Duals vs. Turbos: Know the Law

AidenShaw said:
If you have a single thread, the 4GHz single will tromp the 3GHz dual.

I'm not trying to simply argue, I just want people to realize that a dual is almost never twice as fast as a single. YMMV. Thanks for listening....
Click to expand...

Actually, the dual is NEVER :eek: twice as fast as a single (of the same speed). The principles involved are described by Amdahl's Law.
 
MikeBike:

Most Apps are Multi-Threaded!
Click to expand...
Yeah threads are an effective way to handle ansyncronous operations such as user interface, network IO, and file IO. However those handler threads are typically not doing anything remotely strenuous, they spend vitually every moment of their existance blocked, waiting for something to happen.

When people talk about multi-threaded things they tend to be talking about threads that speed things up, which the IO threads do not in a typical situation.
 
DOS is dead

Most apps that people use Macs for are MULTI-THREADED.

FCP - Parallel renders
DVD SP - Parallel renders / encode-decode
Macromedia anything - multiple filters
Adobe Anything - ditto
iAnything - encode-decode ( iTunes ) parallel renders ( iMovie )
TOAST- Background renders and burning
XCODE - compilation, code assistance.
Cinema 4D - rendering
Maya - rendering
Any web browser, with the possible exception of lynx multiple downloads, parallel rendering of graphics
etc ( name many things ).

While YMMV, you shouldn't necessarily count on your **system** doubling in speed, but simply not bogging down as much when doing multiple things. The amount of parallel processing varies oddly enough by manufacturer, and some applications will be up to twice as fast. Average increase is between 50% -> 80% for many apps. Apple products have proven to be highly effective in threading, while adobe products seem to be the most inefficient. Corel Bryce has/had no threading what so ever so extra procs mean nothing for this application. Several publications from DV to Mac Addict to DMN has hi-lighted these apps and efficiencies at one point or another.

For those who want to stay with the position that DOS lives and most all apps are single threaded, please provide a list of popular Mac apps that are single threaded. I have given you one ( Bryce ). Another would be Access, but that is on Windows ( Strange for a DB to be that way ).

I still believe that for the MAC market, you will find a lot of main stream apps that will make a lot of use of dual core / dual procs.

Max.
:D :D :eek: :eek:
 
maxvamp:

You're way too excited about that. Only some programs are threaded, only some parts of those programs are threaded, only some of those parts are going to be able to use more than two processors, and even in cases where many processors are used, performance will never scale linearly with the number of processors. This is a case of serious diminishing returns.

The natural state of programs is single-threaded. There's nothing DOS about it, its just the natural state of things.
 
Getting a Dual Processor Machine is well worth it especially with Macs. Apple historically charges only $300 more for that second processor considering all other aspects of the configuration is equal. So when spending $1500-$3000 on a machine the cost of having that second processor is only about a 10-20% increase in price while performance should average to about 50% improved overall when you average common fucntions and applications.

http://barefeats.com/g5.html

http://barefeats.com/pm1000.html
 
ddtlm

I have thrown down the gauntlet.

Please provide a list of non threaded Mac apps.

I will agree that the programs I mentioned do not scale linearly. That is why I gave some general stats, of which none mentioned, or should have mentioned 100% increase. Yes, the entire program is not always heavily using threads, but many action of those apps are not time consuming. Those apps mentioned, however, generally do the threading when it counts. In this respect, they are notorious of reducing the time it take to render / compile.

For those trying to make a living with this prosumer machine, this is where it counts most.

( DOS == singleThreaded) && ( OSX != DOS );

Max.
 
jbro said:
All I want to know is - when can I get a G5 laptop?!!?!?
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You'll be waiting another entire year by my guess. Possibly announced @ MWSF, not shipping until 3 months later. And that's if you're lucky, I could see them not even being announced until summer...
 
macsrus said:
NT 3.1 was the first Windows NT (There wasnt a verson 1.0 thru 3.0)


Yes, I think we all know that. It's been called Windows NT for so long now that it's easy to forget when you are writing late in the evening. It wasn't really worth mentioning as it doesn't change the argument.
Click to expand...
 
maxvamp said:
Melgross and Aiden,

You both are trying hard to take the original comments and skew them out of context to make an untrue point.

Threaded tasking happens all the time in many programs. Mail.app collects mail from multiple mailboxes at once while indexing and doing other tasks. Safari does not download graphics sequentially. Framworks used to build a program, such as a UI **is** part of that program.


Max.
Click to expand...

I know what you're saying, but it doesn't get to the heart of the matter. The threads that we are talking about are threads that split the processing of the problem the program is working on, into two or more "chunks" to be worked on in parallel, such as video processing.

I wonder if people are reading this entire discussion, because these questions have been answered before, several times already, in fact.

I don't know how Aiden has the time to answer each question so promptly. I would love to, but don't have the time. Fortunately, he does it well.
 
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