single or dual?

[Veldek]

Hi there!

I'm looking forward to buying a PPC970 (hope the rumors are true...), but my question also affects actual G4s.

I just use my computer (iMac actually) at home, for web surfing, word and excel stuff (also waiting for iWorks...), playing the latest games (when shall Doom III arrive?) and some basic photoshop work etc.

Should I get myself a dual proc computer or will a single proc just be enough? Waiting for your remarks...

 

[markjones05]

Re: single or dual?

Originally posted by Veldek
Hi there!

I'm looking forward to buying a PPC970 (hope the rumors are true...), but my question also affects actual G4s.

I just use my computer (iMac actually) at home, for web surfing, word and excel stuff (also waiting for iWorks...), playing the latest games (when shall Doom III arrive?) and some basic photoshop work etc.

Should I get myself a dual proc computer or will a single proc just be enough? Waiting for your remarks...

Doom III looks sick. Dualies are the way to go on that if you have the cash. But I think that a single would work fine also.

 

[applemacdude]

get the dual...faster, better

 

[Bear]

Re: single or dual?

Originally posted by Veldek
...
Should I get myself a dual proc computer or will a single proc just be enough? Waiting for your remarks...

It sounds like you may not be a heavy enough user where the speed of dual procs would make a difference. This is something you have to decide for yourself.

Also, you need to factor in your usage growth over the period of time you would be keeping the machine.

For me, right now I could use a faster dual proc system, but it doesn;t sound like you're going to use your system as much as I use mine.

 

[Wyrm]

There is something intrinsically cool about a dual processor setup... rather like the difference between a run-of-the-mill Honda V4 engine, and a sleek and sexy Jaguar V8 engine. It all comes down to the size of your pocketbook.

Let me put it this way too: OS-X (Mach actually) - was designed for high performance multi-processing.

-Wyrm

 

[Mr. Anderson]

Given that you're thinking of Doom III, the game is designed to only work on the fastest machine available at the time, and then only marginally. If you get a dual 970 (which is what I plan on doing) it will last you longer as a good platform for future games in the years to come.

Now, as to whether Apple delivers this right off the bat remains to be seen.

D

 

[MacFan25]

It sounds like you aren't too heavy of a gamer, so a single would probably be fine. But, if you want, you could get the dual.

 

[markjones05]

To re-cap:

Single- enough to get by.

Dualies- better, cooler, faster.

If your in to games, especially Doom III which is going to be groundbreaking in graphics, definately go with the duals. I find myself doing things on the duals that I never thought I would. But now that I can... it's a whole nother story.

 

[ktlx]

Re: single or dual?

Originally posted by Veldek
Should I get myself a dual proc computer or will a single proc just be enough? Waiting for your remarks...

I do many of the same things you do except for playing games. I have had both single and dual processor Power Macs over the past three years.

For nearly everything I do, I see almost no benefit to the second processor. However there are some cases where the dual processor machines are smoother in Mac OS X.

The question is how much money do you want to spend? I could easily afford my dual processor Power Macs so I bought them. But if I was on a budget, there is no way I would cough up the extra money. In my experience, it isn't worth the extra money.

But then again, I don't play games. The only CPU intensive stuff I do is all in Photoshop.

 

[Latino]

Originally posted by markjones05
To re-cap:

Single- enough to get by.

Dualies- better, cooler, faster.

If your in to games, especially Doom III which is going to be groundbreaking in graphics, definately go with the duals. I find myself doing things on the duals that I never thought I would. But now that I can... it's a whole nother story.

Doom III is SMP aware? That's the first I hear.

I my experience, very very few games are designed to run on multiprocessor platforms. And those that are (quake...) see very little improvement over a single CPU setup.

Now, as per your requirements, there is another thing you can do with a multi cpu computer very nicely. If you are anything like me, you'll often be doing a trillion things t the same time. If you are doing two tasks at once (ripping some mp3s and, say, doing some photoshop work), then each CPU can be working on each task independently, which will make things a lot faster.

Also, if one CPU is very busy doing something, you still have the other one available so that the system will remain responsive when you click on different windows and stuff, which is always nice, although OS X multitasking should take care of that.

To sum up: If you multitask a lot, or run any SMP aware application that requires power, and have the money to spare, go with the dual. If your main reason is to play games, don't bother and get the single (assuming Doom III is not SMP aware).

There is also the issue that duals usually have two FASTER cpus than the singles. Much like now, the single is 1Ghz, and duals 1.25 and 1.43. So an increase in performance is guaranteed by that fact alone.

 

[benixau]

hey - NEWSFLASH - under OS X the app doesn't need to be multi-processor aware to benfit from having two of those things.

It works like this, say whil you are playing DoomIII:

Proc 1: window server .....
Proc 2: Doom III

this way you get an entire proc (or the better part of it) just for the app. It makes life easy. Also all multi-threaded apps can have OS X divide the task between the procs and then return it.

pretty good. I got a dual and the only thing i wish i had got was a DVD-RAM drive with my SD - oh well.

 

[Latino]

Originally posted by benixau
hey - NEWSFLASH - under OS X the app doesn't need to be multi-processor aware to benfit from having two of those things.

Is it just me or this sentence sounds very rude?

Under _any_ smp aware OS you'll see some benefit by having a second CPU, whether the application in question is SMP aware or not. An OS is always doing several things at once, and the app would have one cpu to itself, while the OS could use the other for its things. But the benefit will, in most cases, be quite insignificant (depending on the app, os, etc)

It works like this, say whil you are playing DoomIII:

Proc 1: window server .....
Proc 2: Doom III

this way you get an entire proc (or the better part of it) just for the app. It makes life easy.

Unless I am very mistaken, if you compare the CPU requirements for doom, and that of the window server, you'll see the Doom CPU at 100%, and the other hovering at around 5% or 10%. This is just my guess. I can't actually test it, but I would be surprised if the window server required so much CPU power.

Yes, all games will see a small improvement by having a second CPU, because that second CPU can take care of things like managing the network trafic, window server, etc, but all that work should be minimal compared with that of playing the game. So the improvement will be minimal, and probably not worth the money. Money that would be better spent on a better video card, or a beer or 10.

Also all multi-threaded apps can have OS X divide the task between the procs and then return it.

I'm not sure if you are confusing multi-threading with multi-processing here. I don't know what your background and knowledge is of this, so I'm sorry if I offend you. But those two things are two different concepts.

Can OSX really asign each thread to a CPU? how does it do this without spawning a new process? please, enlighten me if you know the answer.

Cheers

Latino

 

[ozubahn]

Originally posted by Latino

Unless I am very mistaken, if you compare the CPU requirements for doom, and that of the window server, you'll see the Doom CPU at 100%, and the other hovering at around 5% or 10%. This is just my guess. I can't actually test it, but I would be surprised if the window server required so much CPU power.

That's my understanding too. If the OS X window server actually had to handle the Doom graphics itself, it would require quite a lot of processing power. (Imagine running Doom fullscreen with 50% transparency on top of a few other apps. Ouch.) Fortunately, games like Doom don't bother with the window server much; they go straight to the video card via OpenGL. So you are indeed getting a benefit from the second processor, but the second processor in this case is your video card.

 

[Wyrm]

Originally posted by Latino
Can OSX really asign each thread to a CPU?

Each thread is independently scheduled in Mach, so a process can have two threads operating on 2 cpus at the same time. The smallest part of any Mach program is a thread (a process being one or more).

The problem for Apple, up until the speculated future use of the 970, is the SDR MPX bus, which is somewhat slow even for a single - but the bandwidth is shared between 2 processors on a dual, which means that a dual processor can be more easily starved of data than a single. This is one of the principle reasons (not the only one) that a dual is not 2x the performance of a single. I don't know much about the new 970 bus, except that it is dual channeled and dual pumped, so it may be the biggest factor to an increase in performance rather than a better cpu design.

Latino has a really good point, money IS much better spent on a better video card... especially for games, since it is the user interface experience that determines more how "Fast" you think your machine is, rather than SPEC numbers or theoretical computational power. If you have the money buy both.

-Wyrm