Upgrading h/w for OSX - is more MHz better than dual G4s?

brianleahy

Colonel Panic
I'm currently using a G3/400 B&W.

I'm considering a hardware upgrade. My question is: in OSX (with it's multithreaded capabilities) will you get better performance from a 733Mhz single G4, or a 533Mhz dual G4? There's a $1000 price difference... but if OSX takes full advantage of both G4s, I'd expect that dual 533's would effectively give you nearly 1066Mhz...

How about a 533Mhz dual G4 vs. a 667MHz single G4?

And while we're at it: How about a 450Mhz dual G4? These can be had fairly inexpensively at a couple of online vendors.

Anyone who has any insight into how much difference dual processors make - your input is appreciated.

-BL
 

endian

Dis Member
I'd get the dual - even the 450. There are a bunch of stories floating around about how slow the 733 is.
 

jackd

Registered
Obviously, no single thread will run as fast on a 533mHz processor as it will on a 733mHz processor.

But overall system performance will be better on the dual processor machine.

You may or may not see this increase in individual programs-- few Mac applications are multithreaded. And whether you see any benefit at all depends on how heavily your system is loaded.

That said, I'd still go for the dual procs. I suspect you'll see a significant benefit when trying to do something while Classic is running...
 

AdmiralAK

Simply Daemonic
I heard a rumor that apple will not be supporting dual processors in OS X 1.0.
Whether this means it wont be able to use the 2nd processor period, or whether it will use it baddly I do not know (the article did not elaborate).

I would go with the 733Mhz machine since it does come with a DVD-R/CD-RW drive ;)


Admiral
 

zaustin

Member
I just wanna warn you guys about taking these early benchmarks to heart. Just like the Pentium 4, the 733 G4+ WILL be the fastest single chip solution after recompilation becomes widespread. Just a warning.
 

hELLO wORLD

Registered
I think all depends on the importance of these 1000 $.

I you can afford such a difference, and this doesn't change your life, you can choose the 733 with Superdrive. Of course, if you don't need Superdrive, or saving 1000$ is important for you, just take the dual 533 !
533 single vs 733 is not such a difference, and dual 533 provide a very high performance. Better than single 733 on Mac OS X I think.
I have read that Mac OS X has a 80% (forgot the name) with MP. That means that a dual 533 can provide the same power than a single 850 MHz G4 ((533 + 533) x 80%)....
 

theed

Registered
Most mac apps are very single threaded. If you typically use one mac app very heavily, then you will feel like it has one processor all to itself in a dual environment. The throughput of a single thread would be faster on a single 733, but that's not what feels so great about X on duals. I compress a quicktime movie, and I see Qicktime hog up a processor all to itself. I still use my computer and I don't feel it AT ALL! Essentially all of my other requests go to the idle processor. So theoretical throughput is better on a single processor, but the ability to run full speed background tasks as if they were on another machine, while still using your machine as hard as you normally do... priceless.

As for X not supporting duals, I'd have to say that's crap. Process scheduling is so low level, they'd have to take things out of code they aren't updating to ruin multiprocessing. They might not support 4 processors, but duallies are already done. it's a mach thing. y'know?
 

brianleahy

Colonel Panic
Truthfully, a 733, tasty though it is, is a little out of reach right now. Mostly, I'm considering buying a Dual 450, because of the lower cost.

Obviously, a dual G4/450 is going to be an improvement over my single G3/400, but I was curious about how dual procs stack up against a faster single proc. I may decide to wait another year and save my money.

The Superdrive is neat, but honestly I can't justify the cost. I have an external CDRW that I very rarely use - so it's a little hard to justify spending a lot of cash on a DVD-RW.

 

AdmiralAK

Simply Daemonic
IN the end it's up to you lol,
IN my opinion, apps have not been made so that they can
take full advantage of 2 processors which is something
that is not going to change in the near future. If apple
reintroduces the dual processor line and they become more
mainstream then you will see apps that can handle it better.

The OS can multitask, and use the 2 processors but most of the time you are not copying, deleting and movgin huge files around, most work is done in applications. so IMHO a single processor 566 or 633 might be better if you are looking at price as well (damn costs :p )


Admiral
 

I_GOT_A_G4

Registered
Go with the 633. The dual processor only works with some applications so it is not like you get 1066ghz with teh deul 533. But in the end it is up to u.
 

strobe

Puny Member
Unless Apple recently changed something, only the 633 and 733 G4s have two AltiVec units. The 533DP has one per CPU.
 

saffron

Registered
Hi !

I think it really depends on the apps you use.
For example, Cinema 4D from Maxon takes full advantage of multiprocessing and reaches the speed of 180% (which is the highest possible) compared to a single processor.
Since I´m a C4D user, I definitely would take one of the MP-apples.

CU,
saffron
 

theed

Registered
dual processors benefit ALL X native apps. The benefits may not be a dobling of performance, but the nature of the API's in a premptive environment makes it possible to divide up tasks that are going on in the machine to different processors. Only 9 based apps, and some 9 based carbon ports sit really heavy on just one processor. Even then, underlying system tasks like drive and network access will utilize the other processor, so your speed improvement is still noticeable.

As for copying, deleting and renaming ffiles simultenaeously, that's done by the Desktop Application (an application) not the OS. The OS merely provides multitasking, applications use it.

Maybe I live in a different reality, but I keep an eye on my processors all the time, and I can't stand to go back and live in 9. I totally recommend multiple processors, it allows for a more efficient and freeform workflow, and the speed is there. It allows you to be in charge of the computer again, instead of the computer telling you how many things you can do at once.

Once you have two processors at once, you'll never go back. :)
 

saffron

Registered
Yes ! Of course you are right, Theed. I almost forgot all I already read in our german "Macwelt". But C4D benefits also from multiprocessing without OS X, if the information from Maxon is right. With OS X: I don´t see any reason to buy a single processor.

CU,
Saffron
 

AdmiralAK

Simply Daemonic
Wo kann man "Macwelf" finden ????

(lol.. ok incase my german sux, where can one find macwelt ???? I want some extra (interesting) reading so that I can practice my german)

Danke ;)


Admiral
 

saffron

Registered
Sehr gut, Ben!

Sogar als Deutscher habe ich keinen Fehler gefunden.
Man kann übrigens auch einfach einmal http://www.macweek.de ausprobieren. (Die sind bei den neuesten Nachrichten schneller als macwelt)
Sowieso: Einfach mal alles mit ".de" eingeben...

Gruß,
Saffron
 

AdmiralAK

Simply Daemonic
danke schšn ;-)
Ich wird diese seiten suchen und lesen.
LOL...mein deutsch ist nicht sehr gut denn ich studiere die Sprache nut fŸr zwei Jahre ;)


Admiral
 

Pascal

Official visitor
Originally posted by AdmiralAK
In my opinion, apps have not been made so that they can take full advantage of 2 processors which is something that is not going to change in the near future. If apple reintroduces the dual processor line and they become more mainstream then you will see apps that can handle it better.
This comment only applies to apps used in OS 9, but it does not apply at all to anything that runs in OS X.

Indeed, in the new OS, apps are not "metal-aware" like they used to be in OS 9 (and they have no need to be). By "not metal-aware", I mean that applications cannot directly see the kind and the number of processors available. All this power management is done by the OS in a maner that is completely opaque to them. This is great because programmers, from now on, will not have to bother about compiling apps for dual, quadruple or octuple (dream on :p ) processors. Whatever the number of processor available, the OS will transparently dispatch the workload to any CPU available, on the fly, without the consent and the knowledge of the running app.

By the way, this means that if you have a dual processor Mac, runing classic apps in OS X will be much faster than in OS 9, because Classic will take advantage of both processors while OS 9 uses only one most of the time ! ;) On a 533 MHz G4, using hELLO wORLD's calculations, it will be as if you suddenly had a 850 MHz G4 under Classic...

Alles ist gut !
(German seems to be in, these days ! ;) )
 

jackd

Registered
While it's true that apps don't need to do anything special to be dispatched to different processors by OS X, it's also true that the programmer can make apps use multiple processors more effectively by "threading" them-- that is, spinning off separate threads of execution.

For example, IE could handle downloads in a separate thread, which would make browsing while downloading's going on a lot snappier, especially on a multiprocessor system.

One of the things I like about the Be OS is that apps using the standard Be libraries get a lot of threads for free: all the UI stuff gets its own thread, for example. I'm pretty sure that OS X doesn't provide this degree of auto-threading...
 
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