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New Power Macs Have Crippled DDR Memory?
eggboard writes "According to Rob Art Morgan, who has tested this, the new Power Macs from Apple that use DDR (double data rate) memory -- like the Xserve rank-mount unit -- cannot access the memory any faster than the cheaper and slower SDRAM found in the previous system arch. A controller limits the data rate to 1 GB/s, while DDR could work more than twice as fast. Unfortunately, this makes mincemeat of the architecture, as it bus-/memory-bounds 2D and 3D graphics and rendering."
http://www.macosrumors.com/ has a similarly unfavourable article
I've already discussed this on MacSlash, but the problem is that the G4 processors currently shipped with Macs don't support DDR memory via a direct connection.
The closest Moto has gotten is a 8xxx series "G5" processor that supports a RapidIO interconnect. However, this new processor, despite the existence of demo units dating back years, is still effectively vaporware. My understanding is that Apple is backing an interconnect technology called HyperTransport instead.
Any insiders willing to clarify or correct this? Motorola's current financial state is distressing, especially since I live near where they are based. All those layoffs...
Those who complain about affect & effect on
The only thing that's really changed is that now all my PC133 SDRAM's are no good in the new machines, and I have to start buying PC2700 DDR stuff. This is depressing. No wonder the machines didn't actually go up in price. If they had, then I'd have to pay more to get the *same* performance as before.
before drawing any conclusions from this article.
I don't exactly blame Apple for this. I mean, some people might perhaps consider it deceptive (if it is accurate), but the way Motorola has been dragging its feet for the past several years has put Apple in a really tough position. They can just barely get Motorola to squeeze out enough improvements that the hardware is usable. Everybody has been telling Apple they need to move to DDR, and meanwhile old man Motorola just lets Apple down again and again.
Maybe this move is hoping partly to twist Motorola's arm that this is how it's gonna be with RAM so they should get their act together?
I actually just hope that Apple ditches Motorola altogether and lets IBM do their thing.
If you want to make an apple pie from scratch, you must first create the universe. -- Carl Sagan
I didn't dare look up. Laying face down in the dry grass, my eyes were watering from the pollen and dust, but I was too frightened to sneeze. Each time that I inhaled, the sound in my ears was as loud as howling wind. My fear, however, kept me from exhaling in a smooth and natural way. Instead, my breath came out in a stuttering fashion, as if there was a faulty valve in my throat. She was standing no more than five feet away and spoke in a whisper that was not quite threatening, but was clearly distinct and menacing in its calmness.
"Come on, you fucking baby. Let's play."
I wanted to cry. The "play" wasn't fun anymore, and my helpless state as I lay here in the grass was the consequence of pursuing her dangerous form of "play" a bit too vigorously. At one time I used to dream about being in this very position. I had fantasized, in the midst of mounting sexual excitement, that I was under the complete control of a dangerous and dominating woman who, with the blow of a hammer or the twist of a knife could bring me to the delicious and painful brink of death. She could prolong my physical suffering while preserving my mental pleasure, never quite letting me die, but making me think that at any moment I would. She would be a woman capable of tricking my body and emotions, thereby bringing me that state of intellectual pleasure that no individual can bring to himself. I would be introduced to nothingness, swim in its warmth, feel its fullness, and then be pulled back at the very moment that I was about to be dissolved in it. This evening my pleasure in the fantasy evaporated with the intellectual understanding that I would not return. She was breaking the agreed upon rules of the "game" tonight. Instead of tricking my instincts, she was using them as a conduit to my intellect. I would soon be dead.
2.
In truth, the development of a sexual fetish is not that dissimilar to the development of any other type of taste or predisposition. Remember the first time that you smoked a cigarette? Remember the unpleasant taste of burning paper and tobacco as it filled your mouth with that unfamiliar thick smoke? Remember the first time that you inhaled that same smoke and it burned your lungs? You painfully ejaculated blue-grey clouds out into the air with a loud, deep cough, signaling to everyone that this was your first time. It was not to be your last, of course. You learned to enjoy those very same sensations that had initially caused choking discomfort. You relaxed and took pleasure from the way the smoke slid through your throat and into your lungs. You learned to hold it in for a moment and then expel it, this time with no coughing. The light headedness which had at first nauseated you was now a soft diversion from the world. For the length of a cigarette you learned to control your bodily reactions. Your intellect gained a special pleasure in reinterpreting these reactions through the lens of discipline, undermining all that was automatic and natural. You learned to appreciate the taste of certain poisons, and dislike the tastes of others. American cigarettes have a generally honest, sharp taste while British cigarettes taste softer and somehow mildewed. Like their British cousins, Canadian smokes seem stale, yet they are nowhere near as repugnant as the French product. The reigning kings of all cigarettes are Turkish. The Turks have developed the most truly delicious cigarette ever manufactured. Yes, you learned to smoke for pleasure, but it didn't start out that way.
Sexual fetishism develops in the same way as cigarette smoking. The first introduction to sex is unpleasant and embarrassing. There's the groping and uncertainty. How do you know what the other person is thinking or what she wants you to do? There's slobbering and kissing, grabbing and squeezing. There's insertion and pumping and a growing crescendo of confusing lust and excitement. Soon, it's over and the natural course of the drama is complete. Instinct tells you that something important and potentially dangerous has just occurred; that you've done something to expand the genetic pool. But this is a trick since your intellect knows that a birth control device has short circuited the act of procreation. You learn that sex and reproduction are not necessarily associated. Sex is a pleasure to be cultivated, and your special tastes, though perhaps unusual, are to be respected.
Some men find that their special taste is in blond women, while others prefer black women, or Asian women. Still others discover that a certain kind of dress or underwear provokes the desired mental state towards which the sexual act becomes directed. Some don't even desire women, but prefer other men, children, animals or themselves. Those with the most highly developed tastes tend towards the really exotic. Their disciplined minds overthrow the order that nature has imposed upon them and they learn to desire the most degenerate specimens and activities. The incompleteness of an amputee promotes a feeling of mental completeness, and in stroking the end of a stump the troubles of the world seem far away. Sinking into the folds of a morbidly obese partner reassures that you are safe and that all is well. Spilling urine and feces onto the chest of your partner reminds you that your filthiest functions arouse, excite and are valuable to some people. But then there are those whose tastes are so highly developed and honed that they cannot even be implemented because they are simply physically impossible. Some men desire, for instance, to be crushed under the heel of a gigantic woman. Their sexual pleasure is dependent upon a fantasy of complete powerlessness to a non existent creature. Others imagine themselves to be wild animals with none of the thoughts of human beings. Their ironic desire is to become mentally nonhuman in order to experience raw passion through a human body. These desires, perhaps bizarre, are simply the result of a progressive sharpening of tastes. Each of these individuals desires to experience a very specific mental state. The intellect becomes the main organ for pleasure.
3.
I first saw her at the bank standing in line ahead of me. Her facial features were of ambiguous ethnic heritage, but it wasn't her face that kept my attention. It was the dragon tattoo creeping up the side of her perfect, unblemished thigh, poking its head underneath her very short skirt that held me fixated. I instantly wished that I was that dragon so that I could live my life with my head buried in her crotch.
Her name turned out to be Mina. She was a secretary at a local law firm who hated her job, but loved the effect she had on men. We drank some coffee together and talked. All of the time it was obvious to me that this talk was simply a prelude to other things. What else was obvious to me was that Mina had had this kind of talk with many other men. She was doing her form of research, feeling out the mental territory that she was out to conquer. I liked this. She was in control and I trusted that she knew what to do. I was there to be played with by her.
As it turned out, Mina introduced me to sexual activities that I had never dreamed I would consent to. The "play" began sedately enough; if you consider bondage and submission to be sedate. Mina enjoyed being in a position of dominance which included not only the physical situation but also the mental situation during sex. She restrained me, slapped and spanked me and had me suck her toes. This slavish posture suited me and I quickly adapted to the role in which I had been cast. (A role, incidentally, that could not easily end at the completion of our "games." I'm sure you've noticed that when you become friends with a person, you become accustomed to dealing with them in a very specific way. The initial conditions under which a relationship is established sets the tone for that relationship forever. The relationship between Mina and I was the relationship between a master and a slave.)
Mina's tastes dictated my tastes. She introduced me to the playfulness of dominance and submission games as a first step in my development. It was here that I learned the pleasure in abandoning all responsibility. I became an inactive child. I became a passive "thing" capable of deriving pleasure not from genital stimulation, but from an awareness of the uneven power balance between me and my partner. The less power that I asserted, or was capable of asserting in the relationship, the greater the feeling of pleasure that I derived from the experience. I was tasting the abyss and slowly moving towards the warmth of nothingness. As a man I had responsibility and asserted control. As Mina's "thing" I was less than a bug. I was a fluctuation in the fabric of space/time. I was a wrinkle on the surface of the ocean. I was an ugly reflection that disappeared when the mirror was turned away.
The problem was that I was still more than nothing.
In the attempt to overcome my "thingness," Mina subjected me to enemas, branding and shit blistering. This last ordeal consisted of Mina injecting her shit underneath the surface of my skin until a blister formed. I was ordered to allow the blister to fester for days until she would order me to tear it open with my own teeth. As she berated me verbally and beat me with a television antenna I would lick my wound until it was clean of all pus and shit. We engaged in this drama a number of times, the blisters becoming bigger and more numerous each time. It wasn't long before I became sick. A painful and persistent nausea became a constant presence for me, but Mina refused to allow me to see a doctor. She would call me a "fucking little baby," and force me to lick her anus while she sat on my face and farted. She felt smooth and slick as she slid back and forth over my nose, and the sensation of her soft brown thighs gripping my head threw me into fits of excitement. But this highly pleasurable experience became associated, more and more, with the stench and filth of her bowel excretions. I could not separate the pleasure of having sex with Mina from the displeasure of being forced to wallow in her excrement. Being a helpless mastabatory aid and shit receptacle became an important and indispensable part of the sexual act with her. The more of her shit that I was forced to eat and have injected under my skin, the sicker I became. Yet I could not stop seeing her. More to the point, I did not want to stop seeing her. I craved the humiliation that she subjected me to in my pursuit of nothingness. I was becoming less and less of what I had been by virtue of the fact that I was becoming less and less of anything. Soon I would disappear and never experience pain again.
4.
The intense pleasure of sexual union is always accompanied by a proportional discomfort which arises from the fact that everything afterwards seems painful in comparison. Living involves anxiety and the flight from pain towards pleasure, but it is only the human animal that has the ability to reinterpret his pain as pleasure. Ever since exiting the womb, this intellectual capacity has allowed man to survive in the most unusual and hostile of circumstances, perpetuating ways of life that would otherwise be seen as "unnatural." The ultimate desire of all men is to survive in a prolonged and predictable state free from suffering, and the ability to control one's mental evaluation of the environment is one way of accomplishing this. In the end though, nothing (except "nothing") promises uninterrupted, eternal certainty.
My rackmount server is going to suck at 3D games. Crap.
Guess that makes it Intel 1, Apple 0 eh pudge?
The base configs of each machine are NOT listed.
The base OS configs of each machine are NOT listed.
The combined running configs, ie, size of objects, optional software (especially 3rd party apps and gui-players), etc, etc.
Guess what - each of the above - without running a single line or click of a benchmark can help in determining the outcome.
I'll wait to see how bad or good the new machines are - but I can tell you in advance, the old dual 1Ghz machines and the new ones are not identical at all in the CPU area.
Some folks have to learn to read and understand specs before jumping up and down and screamming.
Just my 2 cents, from the peanut gallery here in NY
Gil
-- Where ever you go, don't complain, you went there!
The DDR is underutilized only for CPU based operations. DMA and AGP based operation will get a boost from DDR.
The data rate between CPU and RAM is limited to 1.3 GB/s. However there is still more than 1.3 GB/s of bandwidth for the GPU (AGP 4x which goes at about 0.5 GB/s), DMA calls from hard disks, etc. So graphics and rendering are not strictly bus-limited, as the GPU can never fully stress the bus. Furthermore, the GPU wasn't tested in the BareFeats benchmarks!
Furthermore, don't forget that the L3 cache on the new 1GHz Macs is only 1 MB, not 2 MB as it was in the previous 1GHz Macs (and as it remains in the 1.25 GHz Macs).
All these benchmarks teach us is that CPU-limited tasks like those posted at BareFeats are not a good test of the added throughput between the system controller and RAM. We need to see benchmarks that stress all of the throughput, not just the portion between CPU, controller, and RAM.
Can't you see that everyone is buying station wagons?
So we have an article which misses a few important points at the generally iffy barefeats, this is then compounded by the comment "cannot access the memory any faster than the cheaper and slower SDRAM" which misses the mark even further. It's a real shame when these things spread around as "the truth" especially on somewhere like slashdot.
Yes the new motherboards are not full DDR, this is mainly because the processors available from Motorola cannot handle DDR FSB's and therefore a full DDR motherboard. This is a shame, but it is far from crippled DDR RAM. Many early DDR RAM x86 motherboards were the same, only the RAM was DDR, not the full motherboard and processor FSB. While this does mean there is still a bottleneck (in certain tasks) between the processor and other components there are advantages to having DDR RAM. The tests at barefeats are using purely CPU limited operations, which will obviously show no real improvement as there has been no CPU or bus change (although the new 1Ghz procs have only 1Mb of DDR L3 cache versus the old 2Mb DDR and a 167Mhz bus version is available). What DDR RAM will help with is when there are a variety of components (CPU, HD, network, AGP, PCI, Firewire, etc) all vying for valuable memory bandwidth. It's these 'real-world' situations when we will see a performance increase. If you just run single process, purely CPU intensive tasks then maybe these machines aren't for you, but if you run a lot of stuff at the same time, or anything that uses CPU, HD, AGP etc intensively and concurrently then you should see an improvement. Things like Quartz Extreme will be throwing a LOT of data at the AGP bus, with DDR RAM this won't have to wait it's turn while say your CPU is busy grabbing all the bandwidth. I'd say many users have a lot of HD, CPU, GPU and network activity going on simultaneously, especially 'power' users. Hopefully we'll see some more benchmarks that show a variety of tasks being performed on these new machines once more people (and more reputable sites) get hold of the machines. While not fulfilling everyones dreams, I'm sure that the statements about the DDR RAM additions being a "waste" or "crippled" will be shown to be entirely false.
I wrote a lenghty debunking of this, but deleted it.
What's the point?
It doesn't matter how stupid, incorrect or subtly falsified the sophistry is-- if it bashes Macs, it gets posted to slashdot.
Its a dick thing-- nobody wants to think their dick is small, so everyone will gather around and argue about whether Macs are inferior or not.
And of course, slashdot likes controversy these days.
So, I'm going to stop taking these bashing articles on their merits -- it gets tiresome explaining computer technology to people who should know this stuff, but apparently graduated high school, read a perl book, and decided they are nerds.
Oh, and Ars Technica is the Weekly World News of computer technology. They wouldn't know a microprocessors feature size from a Martian! Baby! Attacks!
Slashdot is quickly going that way as well.
Yeah, and you guys panned the ipod too: http://apple.slashdot.org/article.pl?sid=01/10/23
Apple's pro iron today is quite expandable. If a new IBM chip arrives that can handle DDR memory as it should, your investment in a new Power Mac will pay off in spades with an upgrade from places like PowerLogix and Sonnet. I just upgraded a now-3-year old Power Mac G3 Blue and White (the first Macs with the current pro chassis) from a 350MHz G3 to a 550MHz G4. With OS X on it, this system rocks...and now I'm reticent to sell it as planned.
In any case, the new systems are still a great buy. It's a UNIX box, folks. More processors mean more processes. At least the systems aren't SLOWER. I take the benchmarks from Bare Feats with a grain of salts. As the saying goes, your mileage may vary. I'm betting these systems will rock when the Mac version of Jedi Knight II shows up.
Vos teneo officium eram periculosus ut vos recipero is.
why Apple gets all of its chips from Motorola instead of IBM? Is there some kind of contractual obligation, or does Moto just come out with new chips first? AFAIK, IBM has much more manufacturing prowess (first with copper, first with 0.13, higher yields, etc, etc) and it seems silly for Apple to limit itself to one supplier that has had consistent manufacturing problems ever since G4s went above 800 mHz...
IIRC the northbridge chip in all new world macs is on the daughtercard and can be replaced along with the CPU. These boards could be next-generation-CPU-ready.
The benchmarks are also poor. They appear to mainly be CPU dependent, not memory bandwidth dependent.
>80 column hard wrapped e-mail is not a sign of intelligent
>life
They were just keeping with the grand tradition of not releasing the pertinent info, like most Apple benchmarks (photoshop, for instance). Truly, another Apple innovation (c)(TM). Notice how barefeats actually tried several different things, rather than just one narrow task like Apple likes to. Also, see spec for instance. Notice who doesn't want to play ball? Hmmmm....
I am surprised so much fuss is being made over such silly benchmarks. The tests cited are very obviously stupid. They mostly exercise the CPU and *NOT* the memory subsystem, so the DDR is essentially irrelevant. And since both setups have dual 1 Ghz CPU's, they should (and indeed do) give virtually identical results.
a di d=9610&perpage=1&pagenumber=50
Here is the best summary of these issues I've seen:
http://forums.macrumors.com/showthread.php?thre
Alright, that website told a nice story but it isn't true. The logo was designed at Regis McKenna Inc., a Silicon Valley business consulting firm that then also had a graphics design house internal. They did much of the work for Apple Computer business and marketing strategy, esp for introduction of Lisa and The Macintosh.
The six-color logo was inspired by a series of print posters make for Ford Motor company, think late seventies design.
How do I know this, I used to work MIS there and we had piles of old Macs, including lots of the really early models. Alas, they no longer do consulting to Apple, nor do they use Macintoshes anymore. Held out until 1998 though, so don't bag on them too much.
What I haven't heard anyone talking about is some of the groundwork laid out for later, when they can remove the CPU bottleneck. Some of the more interesting features of the Xserve architechture are: Intervention and Write Combining. Funny, the things revealed by a little research...
I'll keep my QuickSilver 933 for now. Jaguar promises good performance gains, and that's worth the $129 if I save about one hour for one client. (or worth about $500 if Jag gives me an extra hour of quoteunquote free time)
cat
Be aware that the guy who did these benchmarks is a fucking idiot. Just to give an example, one of his standard benchmarks is done by timing how long it takes to get to the bottom of a huge MSWord document, by holding the mouse down on the down arrow in the scroll bars. I wrote to the guy and told him what a MS Programmer told me, all these scrolling routines have a time delay loop, even an ancient slow Mac has the ability to scroll too fast to read. So they threw in a delay loop. All he's testing is how efficiently a delay loop runs, which is variable, partly dependent on the CPU clock speed (they vary the delay based on CPU speed). No valid data can be obtained from this test, no comparison between ANY two machines is valid.
But anyway, I am mightily peeved at Moto, but I don't think these new CPUs are as bad as people think. They're fast enough to rip and burn raw video to DVDRs faster than realtime. It is well known that the existing benchmarks won't be a valid test of the DDR bus. His test were strictly designed to test CPU performance under a single program load. Let me know when someone finds a Unix system with only a single load.
Altivec was created in a joint effort between Apple, IBM and Motorola. They all have patents on the thing, but use different names for it. Motorola owns the name Altivec, Apple the name Velocity Engine and IBM used to call it VMX. AFAIK they all have the right to use the instruction set (but not a name or specific implementation they don't own). The reason why IBM didn't use it was because they didn't see the use of a vector processing unit (in the past). Of course, the G4, Pentium III & IV and the Athlon have shown the usefulness of a vector unit and IBM has changed their stance. The best proof is of course the new 64 bit PowerPC. It has a vector processing unit which almost certainly is Altivec (although they won't use that name). The Power5 will probably contain a vector processing unit as well.
It is clear that Motorola and Apple have grown apart. Apple has had big problems with them for a long time and has looked at other options. They didn't choose to buy Motorola's awful fabs, it's too late to do that know (nor is it smart). No, credible rumors point to IBM. It makes a lot of sense:
- IBM wants to sell more low-range (Linux) servers, so they already need a fast desktop CPU. Why not sell it to someone else as well?
- Apple has a lot of experience with Altivec, it makes sense to work with them to produce this chip (Apple employs some very smart chip-designers).
- Altivec is a respected instruction set. It's proven to work (no need to reinvent the wheel on a risky venture). Tools are available. GCC supports it (and since their servers will run Linux...).
In 6-9 months we'll probably have a 64 bit PowerMac that is very competitive. I can't wait.
The Drowned and the Saved - Primo Levi
Apple has factory overclocked these puppies.
They are 25% overclocked 800 MHz machines hence the 1MB L3s in each of the "1GHz" machines and the 1.25GHz machines are 1GHz 7455s!
Thoughts? Or are these machines just waiting to be overclocked?
Mod parent up.
are not a good measure for memory performance! All these benchmarks are essentially CPU-intensive, or CPU-bound benchmarks. Even if the RAM is 1000x faster, it will hardly show on them. It's so easy to lie in a benchmark...
If he explores all forms and substances Straight homeward to their symbol-essences; He shall not die.
I think the "1 GB/s" was taken from a comment in the original review on Bare Feats. There was an "explanation" posted from a reader that made the bogus claim that the memory bandwidth was limited to 1 GB/s even in the models with a 166MHz system bus. I notice that the revised Bare Feats report has removed that whole section.
Anyway, the thing that stands out about these benchmarks is that the new dual 1GHz has a system bus (and memory bandwidth) that is 25% faster than the old one, yet this made no discernable difference in these particular benchmarks. This isn't surprising considering that these are CPU-intensive tests, but the bizarre thing is the number of people who are claiming that this somehow proves that the DDR implementation is useless, a fraud, etc. etc. They seem to think these benchmarks would improve dramatically if the DDR bandwidth was passed on to the CPUs.
This isn't logical. Why would a real 25% improvement in memory bandwidth have no influence at all on the benchmarks, yet a 100% improvement which would come from a "real DDR" implementation suddenly make a big difference.
The results of these particular benchmarks would be the same because they are CPU intensive tasks and therfore are bound by CPU speed. (That is, for these tasks much more time is spent in CPU processing that in reading or writing memory). There's no magic change Apple could make in other parts of the system that will make 1GHz CPUs process faster than 1GHz.
That isn't to say that the 166MHz system bus and the DDR implementation Apple is using isn't advantageous in generaly system usage, it is just to say that these benchmarks will not reveal those advantages.
- Dennis D.
The only major manufacturer that seems to be missing official SPEC results is Apple. Instead, we get bogus and irreproducible benchmarks like Photoshop and Bryce, both from Apple and from benchmark sites like these.
Why? Is Apple afraid of backing up their claims of "supercomputer performance" with actual facts? Inofficial SPEC benchmarks have shown the G4 not to be all that much faster than a Pentium with similar clock speed.
Does anyone know if these benchmarks test memory throughput at all? I have no idea what the Photoshop "MP" action file test is, or why it's there twice, so I'm mainly curious about that. I can't imagine that MP3 encoding or rendering in Bryce aren't completely CPU-bound.
I'm not a smorgasbord.
Right on, Apple!
The gist? The 1.25ghz machines use overclocked 1ghz chips. The same for 1ghz--they use overclocked 867's. And the fact that Apple put development resources into making this hack work possibly spells bad things for the future of the G4/G5 program at Motorola.