Finally an interesting G5 story - Page 4

[quote]Originally posted by xype:
<strong>Of course it might be that _you_ know better about him than I do. Yeah, that will be it.</strong><hr></blockquote>

Of course I do, Xype's mate, from Innsbruck.

[ 11-28-2002: Message edited by: Clive ]</p>

<img src="graemlins/lol.gif" border="0" alt="[Laughing]" /> <img src="graemlins/lol.gif" border="0" alt="[Laughing]" />

[quote]Originally posted by snoopy:
<strong>1) It might get sticky trying to share one SIMD engine, so do we need two of these also on one chip?</strong><hr></blockquote>

There were some images of a Power4 posted some time ago, the cip layout was basically symmertrical around the centre-line of the chip - so'd I'd pretty much expect a "dual core" to double-up on available units.

[quote]Originally posted by mooseman:
<strong>...not to belabor it...but you Montana city slickers don't know nothing 'bout farmin' 'parently...

quote:
If our hero the 970 kicks in and does as well as it should, Apple/IBM may not have that long of a road to hoe.


....I bleeve round here, we do all our hoeing on rows.

</strong><hr></blockquote>

Sorry— I’m from the city, and around here, all of our Ho's live in skid rows.

Thanks to all for the inputs. I can understand two complete 970 processors on one chip. I figured that sharing things would be a nightmare, but I wasn't sure. Going from 130 nm to 90 nm means the area is cut about in half. So a two core processor would yield the same number of chips per wafer on the smaller process.

I never considered higher clock speed as an alternative, nor making a larger, more complex core, but I was comparing a two core chip with having two single core processors, the dual processors scheme we have today. I believe heat may still be the biggest concern. What I don't know is how heat scales with process size. If the chip area is cut in half, I have a feeling that power dissipation is not cut in half, at the same clock speed. If someone has the facts on this it would be interesting. If heat does scale the same as area, it would be cool. (Oops, that pun was not intended.) It means there can be a two core package with the same heat and chips per wafer, as the present 130 nm process. However, clock speed still enters the picture.

Let's assume we have a 970 processor that has a certain clock speed, which is determined to keep power dissipation within manageable limits. With a smaller process, clock speed can be raised and the processor will still run at this same power level. I see where the trade off may be a two core processor package running at a lower clock speed, or two single core processor packages running at higher clock speeds. The dual core will have better communication between the the two cores, but the two single core processors are each running faster.

If everybody is planning for multi-core packages, there is obviously more to consider. Possibly, heat dissipation for the package is not a limiting factor at all.

[quote]Originally posted by snoopy:
<strong>If everybody is planning for multi-core packages, there is obviously more to consider.</strong><hr></blockquote>

One of the aspects is the purely physical layout bits. The bit of silicon that is "the CPU" has to have hundreds of wire traces hooked up to it, and slammed into a package. The ppc970 (for instance) has 576 wires, 161 signal wires.

If we have two separate CPUs, we have (exactly) twice as many traces coming out of twice as many packages, and we also increased the complexity of the next chip in line, call that the "northbridge". That chip _also_ has to have a lot more wires. One set has to go to CPU1, and one set to CPU2... and all of this needs to be designed/tested to make sure that it can run full tilt without causing radio interference with all the other signals running around.

If we have one CPU with 2 cores, there is a little bit more than double the number of transistors inside - the extra transistors mean that we don't have to go to 1152 pins for our dual-core 970 chip. Nor do we need two separate sets of traces between the CPU and the northbridge. The part that the two cores share is the access to the outside world. All that says is there is some point where it would be cheaper to build a CPU that is twice as complex (dual core) to avoid paying for all the extra wires/chips etc or supporting two physical CPUs.

Or you could think of it this way: 8bit CPUs can be ganged together into truly gargantuan computers that exceed the output of current Macs. Why aren't we doing that? -&gt; It isn't because the 8bit CPUs are expensive, it is all the wiring & design work running all over the place that would make that impractical. Yet the Altivec unit can pretend to be a pile of 8/16/32 bit computers all running the same thing - and do so cheaply.

[quote]Originally posted by Nevyn:
<strong>

. . . If we have two separate CPUs, we have (exactly) twice as many traces coming out of twice as many packages, and we also increased the complexity of the next chip in line, call that the "northbridge". . .

</strong><hr></blockquote>


That's true. It looks like there is more overhead to a dual processor computer than most of us realize. (Makes me wonder how much extra cost there is a PowerMac now that they are all duals.) Yet, there has been so much discussion and excitement about the ability of the 970 to easily work in duals, quads and even higher. It looks to me like it may be a matter of economics. A dual core processor package would cost less. However, we could still have a trade off between a slower, less costly dual core package, and two higher clock speed single core packages, which cost more but may have better performance. (This assumes that power is a limiting factor, as I suggested in my previous post.)

[quote]Originally posted by snoopy:
<strong>However, we could still have a trade off between a slower, less costly dual core package, and two higher clock speed single core packages, which cost more but may have better performance. (This assumes that power is a limiting factor, as I suggested in my previous post.)</strong><hr></blockquote>

And I'm hoping the trade off would be between one dual core 970's... and TWO. You are right, heat dissipation is very important.

I don't know that we'll see something like this:
1.5 GHz dual core ppc 9x0
2.0 GHz single core ppc 970
at the same time. If they can make a 2.0 GHz single core with a reasonable success rate, they can try to make dual cores at that same time. -&gt; any time one of the cores fails they say 'oops, looks like a single core module, throw it in the 2.0 GHz single core ppc box'. But every time it _works_ they have a dual core.

That is, it is expensive to have widely different chip fab lines running at the same time -&gt; they'd all come off of one line. The 'defects' are sold as either lower GHz parts, or single core parts or whatever - but they shouldn't be drastically different. And the dual core parts would always cost more -&gt; tougher to make. (Any time a dual core 'fails' you get a "free" single core)

I have no idea how the heat trade off will end up working though.

Yea but how is Apple going to market dual core CPU's? You can't say dual 1.8ghz or can you? Maybe we'll see dual dual core CPU's...wow! I guess what I'm getting at is if the 970 became dual core would apple still put two of them in their Powermacs? Or would they only put one dual core chip and call it a dual system. To be dual or not to be...

I don't care how they market it, I'll take one to go.

[quote]Originally posted by Algol:
<strong>Yea but how is Apple going to market dual core CPU's? You can't say dual 1.8ghz or can you? Maybe we'll see dual dual core CPU's...wow! I guess what I'm getting at is if the 970 became dual core would apple still put two of them in their Powermacs? Or would they only put one dual core chip and call it a dual system. To be dual or not to be...</strong><hr></blockquote>

Well, They may market a dual core as a "dual" and finally get around to doing a dual "dual-core" and market it as a quad. After all, IBM has been testing uni, dual and quad configurations for some time now. And yes, OSX has been tested with core apps (not to be confused with processor cores) on the first two cases. Unfortunately, we gonna have to wait until the 90nm process is implemented. But just think, when dual-cores do come out, the consumer end of the mac line may get the single core "washouts" of the 970 line.

[quote]Originally posted by Nevyn:
<strong>

. . . (Any time a dual core 'fails' you get a "free" single core)

I have no idea how the heat trade off will end up working though.

</strong><hr></blockquote>

I believe they would cut the power supply to the bad core when they package it as a single core. In that way, it could run at a higher clock rate without exceeding the power limit, or just run cooler at the same clock rate. I'm not sure whether this is what you are also saying.

I don't think there would be enough dual-core failures to create enough washout chips to be used in the iMacs. I would feel funny using a computer a half working CPU. Any way all this dual core stuff is still a long way off. For now we should be more concerned with whether apple will keep the PowerMacs all dual when the 970 comes out.

[quote]Originally posted by Algol:
<strong>I don't think there would be enough dual-core failures to create enough washout chips to be used in the iMacs. I would feel funny using a computer a half working CPU. Any way all this dual core stuff is still a long way off. For now we should be more concerned with whether apple will keep the PowerMacs all dual when the 970 comes out.</strong><hr></blockquote>

Valid points. Maybe enough to sell low priced single processor towers though. Another bad side to it would be the road to single supplier. As it would drive Moto out. Granted, I don't care for Moto's past history, but being limited to a single supplier is worse.

As for Apple keeping all duals ... It's anybody's guess. Mine being that apple will go back to the mixed set (uni and dual models).

[quote]Originally posted by Algol:
<strong>... I would feel funny using a computer a half working CPU. .</strong><hr></blockquote>

Actually, this is what IBM is doing now with the Power 4 chips. Dice that only have one core working are put into lower-end servers instead of the top-of-the-line.

Also, I don't believe that the 'one working core' chips are all that common. It is more common for either both cores to function, or none at all.

Would it be more practical to have a hyper-threaded single core with twice the execution units?

Yea but dual-core sounds better! Imagine the apple adds..." you get 4 CPU's for the price of two!" lol... Or if they cheap us out of the dual configuration they can still claim that the dual core is like having two CPU's. Which I'm thinking it is.

[quote]Originally posted by Outsider:
<strong>Would it be more practical to have a hyper-threaded single core with twice the execution units?</strong><hr></blockquote>

The HyperThreading is supposed to be in the Power5 -&gt; the generation after this. So then you'd have dual dual cores pretending to be dual quad cores via HyperThreading. I can see why Apple is harping on the 'thread everything' mantra for the developers

It isn't something IBM can adopt quickly. They designed the Power4 quite some time ago now - adding a block like AV is a lot easier than rewiring all of the internals for HyperThreading.

I guess the only thing I wonder about wih this rumors is the part about Marklar.

The idea of mass user disatisfaction and defections to other platforms due to the actual implementation of Microsoft and Intel's DRM/spyware efforts isn't new in discussion about DRM. I think it's smart for Apple to want to take advantage of the situation if it occurs. This kind of stuff has just been experimented with so far (A few CD's here and there) but fully implemented Apple could see a significant chance to increase market share.

However, previous discussions about OSX on x86 has centered around Apple's difficulty with chip suppliers thus forcing them to change their hardware to x86 (or perhaps x86 64). These machines would likely be proprietary machines.

This rumor however says nothing about that, instead it seems to suggest that in the event that you had millions of pissed off XP users so frustrated with getting anything done on their machines in privacy that they were ready to switch, Apple would offer them a shiny new OSX CD that they could install on their current PC.

My questions is this. Would Apple really give up control of what hardware OSX is run on and throw themselves back into the "Clone Wars" again just to gain that market share or would they try to get these people to switch to Apple PPC hardware? Some would probably go to Linux rathar than buy a new PC I'm sure but as we all know running an OS on a platform where everyone and their brother builds machines with a hundreds of different possible hardware combinations (chip sets, video cards, network cards, etc) is a support nightmare. Some of the problems with PC's are certainly the fault of Windows but not all. This is where the Macintosh gets it's low total cost of ownership.

This rumor isn't far fetched considering the reaction to Microsoft licensing recently. I have no doubt what has been outlined in this rumor has been discussed as a contingency but I'm not so sure Apple would actually do it.

[ 12-01-2002: Message edited by: nebcon65 ]</p>

Another reason for having an x86 version of OS X could be to run comparisons. Apple can compare how their own applications run on different processors. Even if they never change over, it shows them where more effort needs to be placed in PPC improvements.

[quote]Originally posted by Outsider:
<strong>Would it be more practical to have a hyper-threaded single core with twice the execution units?</strong><hr></blockquote>

The problem with a hyper-threaded core is that resources are shared so that the threads need to be in the same process, and those threads should be doing different things (i.e. integer/float, float/vector, integer/vector). Also, if a manufacturing flaw kills part of a hyper-threaded processor then the whole processor is dead.

Single processor failures in a dual processor chip are common enough that IBM is shipping whole lines of machines based on them! Even if it is a fairly low percentage, this practice is only going to become more common as the number of cores grows. If you have 16 cores and a flaw kills one (or two, or three, etc) of them but your design still allows the others to operate independently, then why not sell it as a less powerful chip? This is going to be as important in the future as selling different chips speeds is today.

[quote]Originally posted by Programmer:
<strong>

. . . Also, if a manufacturing flaw kills part of a hyper-threaded processor then the whole processor is dead.

Single processor failures in a dual processor chip are common enough that IBM is shipping whole lines of machines based on them! Even if it is a fairly low percentage, this practice is only going to become more common as the number of cores grows. . .

</strong><hr></blockquote>

Do you think IBM will ignore hyper-threading, or is there a possibility that it is being worked on for the Power 5, as another post suggested? (I guess if they did do hyper-threading, it would be a reason to use it only with single core chips.) Or is it going to be a contest between single core, hyper-threaded chips, and multi core PPC chips?

[quote]Originally posted by Programmer:
<strong>

The problem with a hyper-threaded core is that resources are shared so that the threads need to be in the same process, and those threads should be doing different things (i.e. integer/float, float/vector, integer/vector). Also, if a manufacturing flaw kills part of a hyper-threaded processor then the whole processor is dead.

Single processor failures in a dual processor chip are common enough that IBM is shipping whole lines of machines based on them! Even if it is a fairly low percentage, this practice is only going to become more common as the number of cores grows. If you have 16 cores and a flaw kills one (or two, or three, etc) of them but your design still allows the others to operate independently, then why not sell it as a less powerful chip? This is going to be as important in the future as selling different chips speeds is today.</strong><hr></blockquote>

Good point but I think that the reason there are so much single core POWER4 with defective 2nd cores is due to the newness of the process and processor. Once these kinks are worked out they should have a higher output of complete processors. Maybe IBM didn't want to dispose of otherwise good single core processors and used them in low end machines. When the POWER4 manufacturing process starts maturing to the point where 95% are whole dual core, it should become economically feasable to just put in the whole dual core POWER4.

[quote]Originally posted by Outsider:
<strong>Good point but I think that the reason there are so much single core POWER4 with defective 2nd cores is due to the newness of the process and processor. Once these kinks are worked out they should have a higher output of complete processors. Maybe IBM didn't want to dispose of otherwise good single core processors and used them in low end machines. When the POWER4 manufacturing process starts maturing to the point where 95% are whole dual core, it should become economically feasable to just put in the whole dual core POWER4.</strong><hr></blockquote>

I think yields in general are lower than you think -- I've heard numbers like 5-15% for the G4, and no higher than 50% even for well-tuned processors in full production. That IBM article on cellular architectures makes a big deal about being able to use chips which have one or more flaws which kill individual cores within the overall chip. That level of redundancy might be able to make yields 95% usable, albeit at a variety of core counts.

I can see the advantage of a cellular approach that would have some 16 mini cores or so. If one, two, or five cores die you would still have viable processor useful for another situation.

[quote]Originally posted by Programmer:
<strong>

I think yields in general are lower than you think -- I've heard numbers like 5-15% for the G4, and no higher than 50% even for well-tuned processors in full production. . .

</strong><hr></blockquote>

It has been several years since I have been connected with IC manufacturing, but that sounds about right for processes a while back. There are a lot of chips on a waffer, and they are tested and marked before packaging. The larger the chip, the greater the chance for a defect. Smaller chips do have a yield advantage. Being able to disconnect bad cores would give some of that advantage to multicore processors. However, a defect anywhere else but in a core still kills the whole chip.

[quote]Originally posted by phishy:
<strong>

During the G4 fiasco, Apple began looking to IBM for its next generation processor. In the fall of 2000, IBM assembled its 970 development team at the request of Apple.</strong><hr></blockquote>

Forgive me, quotes such as this will explain why I don't take these rumors too seriously at all... IBM assembled it's team at the request of Apple... whatever...


Apple is in no position to be picky about speed right now. By the time the 970 is ready to go to market, Intel will be so far ahead of the game Apple won't have a chance. A better speculation would assume that Apple is trying to devise a new business design that would allow the release of OS X onto x86. Thanks to Apple's own "processor wars", consumers are wise to CPU performance. If Apple doesn't approach a standard platform to compete head-on with Microsoft it will show a blatant disregard for the needs of its customers. From a business perspective, x86 offers a lower-priced performance solution with a standard upgrade pricing ramp. Investors are happy, customers are happy--it's a win-win across the board. All that is needed at this point is a strategy to make it work--and I'm not sure Mr. Jobs is our man for the task.

:eek:

[ 12-02-2002: Message edited by: MacLuv ]</p>

Amazing. The chip hasn't gone to market and already it's a wash. <img src="graemlins/oyvey.gif" border="0" alt="[No]" />

Such foresight, MacLuv...


Screed

[quote]Originally posted by Krassy:
<strong>

because the upcoming G3 from IBM will have DDR-Ram support and Rapid-IO and will be multicore superscalar...? (and this all besides the fact that it'll sport a SIMD unit)

edit: i'd call this one a "G5" and the 970 "G6"

[ 11-26-2002: Message edited by: Krassy ]</strong><hr></blockquote>

Not multicore - the G3 architecture was built for speed and simplicity, among other things by leaving out things that support multi-processing.

Similarly, the 970 is not planned to come in multicore versions - after all, it's not a Power4. The 990 family, on the other hand, is expected to include several multicore variations - but that depends entirely on what the market (read: IBM-produced unit sales) looks like by then. Three years is a long time.

Too many comments here are based on an Irish stew-perception of processor-development - "I want some of this, some of that - and then just a quick stir..."

engpjp

[quote]Originally posted by engpjp:
<strong>

Not multicore - the G3 architecture was built for speed and simplicity, among other things by leaving out things that support multi-processing.

Similarly, the 970 is not planned to come in multicore versions - after all, it's not a Power4. The 990 family, on the other hand, is expected to include several multicore variations - but that depends entirely on what the market (read: IBM-produced unit sales) looks like by then. Three years is a long time.

Too many comments here are based on an Irish stew-perception of processor-development - "I want some of this, some of that - and then just a quick stir..."

engpjp</strong><hr></blockquote>

ok i will modify a bit just to clear some things up. the "upcoming G3" will be a next generation chip from IBM. so it's not a G3 anymore.
--- also my statemens are not based on an Irish-stew-perception of processor-development but on the ibm-roadmap
--- further on i never said anything about multicore 970-ppcs ... although i believe further development of that cpu will result in a 970fc or whatever which could be multicored (ok if you want call it 990)...

MacLuv
If Wintel is trying to get out of the old legacy x86 for various reasons whey would Apple try to get to x86?

Yes Intel/AMD have pushed the old cranky x86 to speeds noboyd could have dreamed about. The Pentium replacement was planned to come out 1997 and it is sligtly deolayed but accordning to Intel that is were their future CPUs will be and they ought to knew.

Win XP is made for x86. Mac OS X with the Quarts engine etc is made for CPUs with the Velocity Engine etc. My guess is that even native OS X86 applications would suffer for a long time and then we have all the emaulation code.

Moving from the struggling 68040 to the 601 was a big leap. The 601 was a powerful CPU well on par with the pentiums at similar pentiums running UNIX. In the Mac however the emulation in OS and applications killed the performance completly and the pentium totaly killed those 601 computers.

Some months ago I booted a 7200/90 into the earliest OS 7 that came with the computer. Truly terrible way slower than 8.6!

A migration to x86will set up the Mac for such trouble agian. Not a good idea. In the future when the Macintosh has leaft all the pre OS X legacy behind and the Intel is past x86 it might be a good alternative but now it is not <img src="graemlins/oyvey.gif" border="0" alt="[No]" />

[quote] By the time the 970 is ready to go to market, Intel will be so far ahead of the game Apple won't have a chance. <hr></blockquote>

Well first of all it would be nice if you based your post on real information rathar than a prediction based on previous years advances in the speed of intel processors. Intel itself has projected 3.4Ghz by around the time the 970 would be out.

In addition, just because 1.8Ghz is the target speed for the first 970 chips does not mean that it won't actually debut at 2Ghz or higher once the assembly lines get going.

Thirdly the key word for the 970 is going to be "throughput" it's not just Mhz as evidenced by the preliminary benchmark projections in comparison to the current P4.

What x86 processor do you think is going to go in an iBook a Celeron? Oh please. You know there hasn't been a x86 laptop for a long time that hasn't had a crippled or half baked excuse for a processor in it for a long time. Going to x86 would kill Apple's portable lineup.

The fact that the new 3.06Ghz P4 consumes around 80 Watts and with HT (hyperthreading) enabled can go as high as 105 Watts should tell you that x86 is getting close to a wall. Yeah they are going to 90 nm soon but so is IBM who has been talking about 5Ghz lately. Using 90nm the 970 could probably go into a Powerbook. Intel on the other hand has started to back off speed projections including their coveted 10Ghz mark.

High end x86 processors have run more expensive than the G4 and likely the 970. How many times do people have to explain total cost of ownership? I quote one of my earlier posts

[quote] My questions is this. Would Apple really give up control of what hardware OSX is run on and throw themselves back into the "Clone Wars" again just to gain that market share or would they try to get these people to switch to Apple PPC hardware? Some would probably go to Linux rathar than buy a new PC I'm sure but as we all know running an OS on a platform where everyone and their brother builds machines with a hundreds of different possible hardware combinations (chip sets, video cards, network cards, etc) is a support nightmare. Some of the problems with PC's are certainly the fault of Windows but not all. This is where the Macintosh gets it's low total cost of ownership. <hr></blockquote>

I have seen things in PC support enviroments such as two supposedly identical machines where one refuses to use a video card that the other machine will use just fine. If you unleash OSX onto machines like this expect that and even worse to happen just like PC's with Windows on them. Again some of it is Windows but a lot of it is the nature of the platform.

if you're talking about proprietary Apple x86 hardware AND a port of OSX, the machines would likely not be much different in price at all. They still wouldn't be selling in enough volume to bring the price to the level you expect. The volume you sell does affect the price. Just ask Wal Mart.

[quote]Originally posted by snoopy:
<strong>

Do you think IBM will ignore hyper-threading, or is there a possibility that it is being worked on for the Power 5, as another post suggested? (I guess if they did do hyper-threading, it would be a reason to use it only with single core chips.) Or is it going to be a contest between single core, hyper-threaded chips, and multi core PPC chips?</strong><hr></blockquote>

SMT (Symmetrical Multi-Threading) is one of the planned features of the Power5 which is expected to ship in 2004. There are many articles on the web that discuss this. Here's one:

<a href="http://www.iseriesnetwork.com/resources/artarchive/index.cfm?fuseaction=viewarticle&CO_ContentID=1523 8&channel=" target="_blank">http://www.iseriesnetwork.com/resources/artarchive/index.cfm?fuseaction=viewarticle&CO_ContentID=1523 8&channel=</a>

"Another new feature in POWER5 will be simultaneous multithreading (SMT). The idea behind SMT is to share the processor hardware on a chip among multiple threads in a multiprogrammed workload. In this way, a single processor on the chip can sometimes act as two processors."

Steve

[quote]Originally posted by engpjp:
<strong>

Not multicore - the G3 architecture was built for speed and simplicity, among other things by leaving out things that support multi-processing.

Similarly, the 970 is not planned to come in multicore versions - after all, it's not a Power4. The 990 family, on the other hand, is expected to include several multicore variations - but that depends entirely on what the market (read: IBM-produced unit sales) looks like by then. Three years is a long time.

Too many comments here are based on an Irish stew-perception of processor-development - "I want some of this, some of that - and then just a quick stir..."

engpjp</strong><hr></blockquote>

IBM's roadmap shows the next generation Power PC as multicore superscalar, maybe it'll be a 860 series

[quote]Originally posted by nebcon65:
<strong>
In addition, just because 1.8Ghz is the target speed for the first 970 chips does not mean that it won't actually debut at 2Ghz or higher once the assembly lines get going.

.</strong><hr></blockquote>

Good point, and a precidence is the Gekko, which was delivered faster than the "anounced" speed was 400 mhz, but the shipping game cubes are using a 485 mhz chip.

[quote]Originally posted by MacLuv:
<strong>

By the time the 970 is ready to go to market, Intel will be so far ahead of the game Apple won't have a chance.

[ 12-02-2002: Message edited by: MacLuv ]</strong><hr></blockquote>

underlining your quote ...



Source: c't 25/2002

[ 12-02-2002: Message edited by: tomk ]</p>

[quote]Originally posted by tomk:
<strong>

underlining your quote ...



Source: c't 25/2002

[ 12-02-2002: Message edited by: tomk ]</strong><hr></blockquote>

Umm if that is true it means my iMac 800 is much faster than a 3.06Ghz P4. I get 2703.5Megaflops while the top of the line P4 only gets 1442 Megaflops. Wow I wonder how they got the macs to score so bad in the benchmark?

[quote]Originally posted by Algol:
<strong>

Umm if that is true it means my iMac 800 is much faster than a 3.06Ghz P4. I get 2703.5Megaflops while the top of the line P4 only gets 1442 Megaflops. Wow I wonder how they got the macs to score so bad in the benchmark?</strong><hr></blockquote>

You're comparing the G4's theoretical MFlops to the P4's measured MFlops in a Linpack test, which obviously makes no use of AltiVec, and which has probably been much more thoroughly optimized for the x86 architecture than for the PPC.

The theoretical MFlops number Apple gives for the G4 in your iMac assumes AltiVec running at maximum efficiency.

Apple didn't give me that number... Altivec Fractal did. And I get 406.6 megaflobs with altivec off V.2703.6 with it on. Man altivec sure makes the G4 fast. So guess what guys the G4 without altivec is quite slow, but then again if it didn't have altivec it wouldn't be a G4. So I guess that argument is kind of defeated. Oh well its nice to know that my imac is faster than a top of the line P4. at least according to these tests.

[quote]Originally posted by Amorph:
<strong>
The theoretical MFlops number Apple gives for the G4 in your iMac assumes AltiVec running at maximum efficiency.</strong><hr></blockquote>

The theoretical MFlops number Apple gives for the G4 in the iMac is also much higher than the numbers Algol stated. I don't remember exactly, but I believe it's at least double Algol's number.