Single Processor PowerMacs

arn

macrumors god
Original poster
Staff member
Apr 9, 2001
14,507
1,789
Spymac suggests that an all-dual Pro Line is not necessarily here to stay:

If recent rumors are to be believed, the next Power Mac revision -- still many months away -- will reintroduce the familiar mixture of single and paired-up processors we've become accustomed to.


Dual Processor machines help make up for apparent MHz number differences between current PPC and x86 chips, but increase costs in individual machines.
 

davidf

macrumors newbie
May 1, 2002
5
0
just guessing....

but this means that whatever chip we're moving towards next, will have upwards of 1.4Ghz single processors.

There would be little point updating with slower chips.!

here's hoping they're IBM
 

bobky

macrumors member
Aug 9, 2001
37
0
UK
If we do get IBM for the next chip, would they class dual core as a single processor?

Or does a dual core chip = dual processor in performance etc?

Any one know the (dis)advantages of this?
 

Mr. Anderson

Moderator emeritus
Nov 1, 2001
22,561
0
VA
well, the Power4 could have more than 2 cpu cores - so even though its one chip, it would be a multiprocessor - now, if you had 2 chips - for very high end machines you could end up with 8 or more CPUs on one machine.

Sounds good to me!

D
 

barkmonster

macrumors 68020
Dec 3, 2001
2,123
12
Lancashire
If rumours are true about the IBM chips, dual core would work a lot better than current 2 cpu dual models.

It's got 6Gb/s of memory bandwidth to the cpu compared with the measly 1.3Gb the current models have.

Assuming that the IBM chips perform just aswell as a G4 does at 32bit code, all our applications should run significantly faster on a single core 1.6Ghz IBM chip than on a dual 867Mhz G4. I'm sort of glad I've held off buying a new mac for so long, by this time next year they'll be some seriously fast powermacs to be had and staying beige for 5 years will have be more than worth it.

Dual cpu's never double the performance overall, look at the differences between a 933Mhz G4 and the 1Ghz G4, it's certainly not 114% faster, infact it's only 51% faster. I base this comparison on the barefeats photoshop tests earlier in the year.

Assuming it scales with clockspeed and performs on a par with G4 when running 32bit code, we could say that a single 1.6Ghz IBM chip is going to be 71% faster than the 933Mhz G4 or more to the point 60% faster than the entry level dual 867Mhz G4.

I'd rather wait for a single cpu mac at a reasonable clockspeed and price before I even think about buying a new one, the G4 has always matched the Athlon Mhz for Mhz in every test I've seen, if a 1.6Ghz Athlon wastes a dual Ghz G4 and a 2Ghz Pentium 4 then a powermac at 1.6Ghz is really going to be worth waiting for.
 

bobky

macrumors member
Aug 9, 2001
37
0
UK
now, if you had 2 chips - for very high end machines you could end up with 8 or more CPUs on one machine.

Sounds good to me!

D [/B]
Well if apple wants to get into Hollywood, these are the machines they would need.

Not that I would be buying one next year (quite happy with my current G4) But I sure hope apple get some IBM silicon in their next machine, I dont think it just a case of mhz myth anymore. Apple needs to push their high end market, which seems to have suffered recently. Hence the possible emphasis on other areas, consumer, iApps, .mac etc....
 

mymemory

macrumors 68020
May 9, 2001
2,495
0
Miami
Well... it was obvious that the present line of powermacs was develop to keep stock holders and users "happy", I say that because I do not see the need of a new enclosure or a entire line of dual processor if is not because Apple is facing it is behind in the MHz race.
 

Pants

macrumors regular
Aug 21, 2001
194
3
Re: Single Processor PowerMacs

Originally posted by arn
Spymac suggests that an all-dual Pro Line is not necessarily here to stay:

If recent rumors are to be believed, the next Power Mac revision -- still many months away -- will reintroduce the familiar mixture of single and paired-up processors we've become accustomed to.


Dual Processor machines help make up for apparent MHz number differences between current PPC and x86 chips, but increase costs in individual machines.

Theres nothing 'apparent' about it - 1.25 is definately less than 2.6.
 

macmunch

macrumors regular
Jan 6, 2002
116
0
No...

Now ...

Dual 867 = 1734 Mhz
Dual 1 Ghz = 2 GHz
Dual 1,25 = 2,5 GHz

So when there will be an Single Porsessor version to come back.
It must be an chip with at least 1,8 GHz because Apple says Offical that the new Dual 1,25 is effective 2,5 GHz !!!

So now we have on the entry level machine nearly 1,8 GHz when the next revision will be single 1,4 that would be **** !

That would be a technical Backstep !
And I would never buy such a machine !!!
 

Mr. Anderson

Moderator emeritus
Nov 1, 2001
22,561
0
VA
If the new single chip supports a higher bandwidth, like barkmonster says, it wouldn't need to be 2.5 GHz to compete and definitely not a stip back. But I would recommending not worrying about any of this until the machines come out.

D
 

BigFish

macrumors newbie
Sep 5, 2002
4
0
Denver
Half G4, Half G5 Lineup

What if they intro the new IBM "G5" in the top end machines and stick with dual G4's in the lower ends? That would put a single IBM at, say, 1.6 at the top and dual 1.25 G4's at the bottom. I would assume WHEN these new IBM's make it into the PowerMacs, they will be to expensive to use in a dual config. And since they kick so much butt, a 1.6 would slaughter dual 1.25's.

Just my theory.
 

Mr. Anderson

Moderator emeritus
Nov 1, 2001
22,561
0
VA
that would make sense, and I hope the new IBM chip does what its been rumored to be able to do. We'll have to wait and see what IBM has to say in October....

D
 

e-coli

macrumors 68000
Jul 27, 2002
1,837
801
this is all asuming we're getting a power4 powermac....

It looks as though the powermac line might not need duals. here is an interesting comparison chart of various chips.

I did some reading on the Power4, it said that critical processing errors won't hang up the chip. it bypasses the error, and keeps on truckin'.

combined with mac os x, that would make the powermac line virtually crash-proof.
 

Attachments

porovaara

macrumors regular
Mar 7, 2002
132
0
sf
Originally posted by e-coli
I did some reading on the Power4, it said that critical processing errors won't hang up the chip. it bypasses the error, and keeps on truckin'.
[/B]
Uhm and how does that protect the OS again?
 

e-coli

macrumors 68000
Jul 27, 2002
1,837
801
hmmm.

a system crash in os x was due to a kernel panic. isn't that a critical.processing.error?

maybe not. i dunno.
 

nixd2001

macrumors regular
Aug 21, 2002
179
0
UK
Originally posted by e-coli
hmmm.

a system crash in os x was due to a kernel panic. isn't that a critical.processing.error?

maybe not. i dunno.
The Power4 error recovery features are aimed at detecting hardware failures and working around them. For example, if part of the cache memory stops working. Kernel panics are where a software situation has arisen that the original author did not anticipate, so unforunately Power4 technology doesn't offer anything additional here.
 

sedarby

macrumors regular
May 29, 2002
223
0
Dallas, TX
IBM Power4 jr.

Remember, the IBM chip that has been rumored is not the Power4 they have in production but one they are designing for the desktop. A limited version if you will. So, although the benchmarks look promising, they don't reflect the chip that we hope to see in a new generation of Macs.;)
 

ddtlm

macrumors 65816
Aug 20, 2001
1,184
0
sedarby:

I expect ~90% of the performance seen in a Power4, and even better performance when using the vector unit which the "real" Power4 does not have. It is also possible that the "Power-Lite" will be clocked higher than the big Power4 because smaller chips tend to be able to clock better (heat, yields) and because IBM wants their mega-servers to be super reliable so they are very conservative with clock speeds.

I am pretty sure that a single "Power4-Lite" at even 1.2ghz would be a better machine than our current dual 867 G4. While I don't expect it to offer the full 6.4gb/s on the FSB, it will have more than 1.3gb/s or 1.0gb/s, and if we are lucky it will still sport some nice big L2 and L3 caches (although not nearly so large as seen on the real Power4).

I think the Power4-Lite will be very expensive, and I do not think that Apple would be able to offer a dual setup for the low end, and maybe not even for the middle model.

Anyway, I'm sure hoping things turn out well.
 

ddtlm

macrumors 65816
Aug 20, 2001
1,184
0
e-coli:

Uh, just remembered that graph you posted. I'm sure you realize that it compares the Power4 at max speed to an Athlon clocked at only 1.6ghz (75% of max), a P4 at only 2.2ghz (79% of max), an Itanium-1 which is much slower than an Itanium-2, and an Ultraspac3 which is only 86% of the top end model. Nice way of stacking the deck!

Also, the Power4 error detection stuff you are talking about does not do what you seem to think. It best it will handle hardware problems, but bugs in the OS will still crash it no problem.
 

eirik

macrumors regular
Mar 17, 2002
155
0
Leesburg, VA
multi-threaded

Apple is now enjoying great progress, compared to a few years ago, in having more and more applications be multithreaded.

That said, I wouldn't be surprised if Apple never goes back to single CPU (single-core) configurations in its PM line.

Someone rightfully pointed out that two CPU's does not double the performance... for a single application or thread. But, as more and more of the applications running on and within OS X are multithreaded, and as more and more users are running multiple CPU-intensive applications/services simultaneously, one could say that while two may not double performance overall for a single application, they get a hell of a lot closer to doubling overall performance when running many multithreaded applications/services.

Eirik
 

TechLarry

macrumors regular
Feb 21, 2002
142
0
Re: Single Processor PowerMacs

Originally posted by arn
Spymac suggests that an all-dual Pro Line is not necessarily here to stay:

If recent rumors are to be believed, the next Power Mac revision -- still many months away -- will reintroduce the familiar mixture of single and paired-up processors we've become accustomed to.


Dual Processor machines help make up for apparent MHz number differences between current PPC and x86 chips, but increase costs in individual machines.
"Apparant" Mhz differences?

Sheesh, I can't believe _anyone_ is buying that line any more.

Apple is getting their Ass handed to to them in the performance area right now. It's not apparant. It's reality.

And as a Mac User, it really makes me mad. I use PC's too so I know the truth based on daily experience.

TL
 

Johnny7896

macrumors newbie
Jul 3, 2002
26
0
Omaha, NE
I think Apple will move back to single CPU's. I feel there just tring to use up the remaining G4's. No better way then sell them by duals. They will use an upgraded chip from IBM or Moto. It would be wise to release it before Xmas, but it may wishful thinking. More like MWSF. I'm waiting for the next release of Power Macs. No duals here. I saw the G4 sinking for years and it's still here. Amazing. Talk about milking the G4 for every penny. IBM is more professional in business and structured to give good Apple results on processors. The future will tell.....
 

chubakka

macrumors regular
Feb 27, 2002
123
0
NYC
if intel is so frickin great...

why did it coerce BAPco to fudge the benchmarks
and compromise the "independant" Sysmark 2002...

http://www.theinquirer.net/?article=5274

yeah yeah yeah the P4 is up to 2.6 GHz but...
how come slower AMD chips perform better?
AMD won't even use Sysmark 2002 because
it slants so heavily to Intel.

Yes the PowerPC as a bit of catching up to do...
but it's not as grim as many of you think.

Plus I read that IBM intends thier new PowerPC chip
to start at 2GHz.
 

eirik

macrumors regular
Mar 17, 2002
155
0
Leesburg, VA
Originally posted by Johnny7896
I think Apple will move back to single CPU's. I feel there just tring to use up the remaining G4's. ..
I've had a similar thought on this. Rather than use up an existing supply, Apple would be satisfying minimum volume contractual requirements. That is, Apple might be required to purchase a certain number of CPU's from Motorola. BTW, if this were the case, I'd seriously consider a new top-end iMac that features dual processors. [Not a major point, but iMac sales volumes are quite higher than PM sales volumes.]

All that said, I'm skeptical about Apple being required to buy a certain number of CPU's prior to it being able to move to another CPU. Even so, it is a plausible theory.

As for eliminating existing supplies, I'm not familiar with how Apple inventories CPU's. As I understand it, Apple operates a sophisticated just-in-time production system. So, that would suggest that Apple does NOT have a warehouse full of Motorola CPU's. JIT is meant to reduce inventories of parts, systems, and sub-systems from suppliers. One would stockpile with JIT if Motorola had huge production variances. I think we would have heard of such issues if they existed.

Eirik
 

LethalWolfe

macrumors G3
Jan 11, 2002
9,368
119
Los Angeles
Originally posted by bobky


Well if apple wants to get into Hollywood, these are the machines they would need.

:confused:


Errr... Apple is in Hollywood. 99.9% of everything you see on TV (excludeing news/news type shows that don't do a lot of post) and at the theaters is either cut on Mac based Avid software or FCP 3.0.

Lethal