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IBM PowerPC 970 Architecture
riclewis writes "Hannibal from Ars Technica offers an explanation of some of the internals of the new IBM chip. It's certainly more powerful than anything on the desktop now, but by the time it's released a year from now, it looks to be middle-of-the-pack (which could still be a step up for Apple...) This excitement over the early release of hardware specs kinda reminds me of all the hype surrounding the Sony's Emotion Engine when it was introduced a couple years ago. In fact, some are suggesting the PPC 970 chip might be closely related to the PS3's 'Cell' processor..."
This could help push Apple back to a respectable market share over a couple of years. A *nix box with a decent processor and lots of commercial software? Of course, Apple has proved to be just as fierce in protecting their proprietary code as Microsoft, so I wouldn't expect the price to drop significantly for every million sold. But still, alternatives (especially of this caliber) are good.
Unlike the P4, the 970 does one more trick after it has cracked the PPC instructions down into iops. The 970 divides up the iop stream into "groups" of five iops a piece. So first it cracks the PPC instructions down into iops, then it collects the iops back together into groups. The iops are placed the group's five slots in program order with the stipulation that all branch instructions must go in slot 4 (the last slot). Furthermore, slot 4 can hold only branch instructions and nothing else. It is these groups of five iops that are dispatched in-order to the issue queues. (I haven't yet seen a functional diagram of the 970's core, so I'm not sure how many issue queues there are.)
computing in chunks... sounds a lot like a Cray. Together with the 900MHz-effective (jesus... that's a lot) FSB, Apple really will be selling supercomputers in the next few years.
But what do I know. I'm just looking for anonymous gay sex.
when the p4 debuted it was sort of average too... the p4's power has come from it's ability to scale to higher mHz ratings pretty quickly. what kind of life are they going to get out of this chip? if it's going to top off at 2gHz then it doesn't really seem worth it, but if they can chip can get up to 3 gHz or so within a year of its release...
1) Why all the hype over a chip that will be slow when it's released? I'll admit, the specs look damn impressive - a 1.6 Power4 single-core has the SpecFP/INT specs of a P4 2.5 (500mhz Bus), but they're not due out for a year, and the 1.6 is expected to be on the high end
2) Why only a single-core?
3) Where's the G5? It looked similarly impressive, a year ago. It still does, according to the Register's leaked spec numbers
4) What's the advantage again of a 64 bit processor? Sure, more RAM. Is it faster? Does it do more? Anyone?
4)
"Sometimes a woman is a kind of religion, she can save your soul & set you free from all your sins" - Bad Examples
... so could somebody who understands this processor tell me this:
Would a 3D rendering app such as Lightwave potentially see a huge benefit to this processor? I understand that it's up to the developer to tune it, yadda yadda yadda, I'm concerned with potential not real world numbers.
I'm trying to get an image in my mind about how the various processor descriptions (32-bit, 64-bit, Altivec, SimD, etc...) can radically change how an app like that would work.
Us vertex pushers have a substantial interest in machines that excel at that type of work...
Oh wow, now that brings back some memories! I remember a friend of mine bringing over this ST he got at a garage sale and had a Mac emulator disk on it. Since I was a Mac person and he wasn't he asked me to help him get it running.
We managed to get System 7 running on it and even managed to coax AOL 2.x to run on it via the modem, getting it online! It was slow and it was AOL running on a Mac emulator on an Atari, but hey, it was geeky and it was fun to do.
But back on topic, if they do use the same or similar chip it could possibly work though Sony would DMCA it straight to hell.
--Won't that be grand? Computers and the programs will start thinking and the people will stop. - Dr. Walter Gibbs
Also keep in mind that SPEC marks are *highly* manipulatable. Here you have a benchmark that is supposed to test the CPU. The problem with this is that is both compiler dependent *and* OS dependent . As has stated many times before, the current G4 machines score in the low 300s in SPEC marks. Does this mean that the G4 is 3 to 5 times slower than the P4? In practice, it isn't. Yes, the P4 2.8 is much faster than the current G4 in most day-to-day activities, but not by *that* much. Anyone can "cook" SPEC marks.
What you *really* want to do is use the machine, *then* consider whether or not the machine is fast enough for your purposes. Personally, I think that machines with the 970 in them will be quite competitive with the machines that are available at launch.
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Blocklevel: Practical Information Architecture
Since I won't be buying a pc from Apple with this chip on it, I hope some third party such as Tyan decides to make an ATX format MB for us pc builders. There WILL be Linux ports for this chip, and existing PPC ports would probably work with it in 32 bit mode at first. Even IBM might offer an ATX evaluation board, though it would probably cost too much.
You are right, most of us can't wait, at least those of use with really old Macs (about to retire my Beige G3 in fact). I just ordered one of the Dual 1.25 GHZ machines and that should be more than enough power for me for some time. I'll move up to a 64 bit Mac in 3-5 years when they've worked out the kinks and about the time most people quit making 32 bit apps.
I did at least learn my lesson with the Beige G3 when it comes to jumping onto the latest thing just as it first comes out. While my old Beige G3 Rev A box has been a fairly solid machine for the past 5 years, it does have some serious shortcomings (possible voltage regulator blow out if upgraded to a G4, 66 MHZ bus (ick) and Rev A rom means no IDE slave support!).
I feel fairly confident this possibly last of the line G4 should be fairly solid other than the chips not fully utilizing DDR (at least DMA operations will take advantage of it) and the silly idea of making the second IDE channel only ATA66.
Once the issues of moving to a 64 bit chip and the new Hypertransport bus and such are worked out and my machine starts to look as slow as my Beige G3 is now compared to the latest machines, then I will start itching to move up.
--Won't that be grand? Computers and the programs will start thinking and the people will stop. - Dr. Walter Gibbs
Alright, I'm sooo tired of this argument. First of all, just because it is a RISC chip, doesn't mean that a 1.0 GHZ motorola chip in a Mac could even come close to outperforming a 3.06 or even 2.80 GHZ Pentium 4 when combined with a 533 FSB and RDRAM. Apple just recently adopted DDR ram, but get this - the little PPC chip you have isn't even natively able to support it at DDR speed, the current batch of PPC chips can only work on one swing of the computing "cycle", not on the up and down like an Athlon can for example. Meaning, the motorola chips are not double pumped, so Apple is years behind AMD and Intel right now. Your argument doesn't hold water.
Also keep in mind that SPEC marks are *highly* manipulatable. Here you have a benchmark that is supposed to test the CPU. The problem with this is that is both compiler dependent *and* OS dependent.
Indeed. SpecFP has almost been reduced to a memory throughput test. What kind of bandwidth will the (hypothetical) Apple chipset deliver? Also, are these numbers base or peak?
Not to mention published Spec numbers must use a production system..
The law is a weapon of the government, not a protection for the likes of you. Surely you understand that.
"Hannibal" also has an incredible knack for making the workings of microprocessors understandable to those with no hardware engineering backgrounds.
// I will show you fear in a handful of jellybeans.
two advantages to this processor are the bus--900mhz with 6.2 gb/sec--and the power usage.
"At 1.8GHz, the PowerPC 970 will consume 1.3-volts and dissipate 42-Watts. At 1.2 GHz, the PowerPC 970 will consume 1.1-volts and dissipate only 19-Watts. For comparison, a 1GHz G4 consumes 1.6-volts and dissipates 21.3-Watts."
it seems that the powerbook potential is there. and in apple's market data throughput counts heavily, maybe more than absolute processor speed. look at sgi. the ibm proprietary memory is a bit confusing however.
Is it me, or does saying that an 800MHz G4 is about twice as fast as a 450MHz PII not sound like much of a statement?
Perhaps if you said your 800MHz G4 was twice as fast as your 1.2Ghz P4, I would be impressed.
Personally, I think you must have made a typo.
There they were, sitting in the van with all those dials, and the cat was dead. -V. Marchetti, CIA
Good lord, not this argument again.
First of all, whoever modded this as interesting should be poked in the eye. This statement is full of FUD to the max.
Perhaps a G4 will outperform an x86 of the same caliber, but the high-end P4 CPUs absolutely smoke the high-end G4s. The G4 architecture is so maxed out that Apple had to resort to adding a second CPU, cuz they just couldn't scale the G4 chips any higher.
When the G4 came out, it kicked the arse of all the x86 chips out there. But that was a couple years ago. As things currently stand, the best Apples are barely middle of the pack, performance-wise. Don't worry though, you'll still pay more for a Mac than a fully loaded Dell machine.
The 7.2 GB/sec of bandwidth is just not much more than double that of existing P4s (P4 = 4.2 GB/sec) and since Hammer will have 6.4 GB/sec in early 2003, should be essentially the same as competing x86 chips.
A deep unwavering belief is a sure sign you're missing something...
SpecFP has almost been reduced to a memory throughput test.
>>>>>>>
Because in this age of 128 bit vector fp units, fp in general is basically a memory throughput thing. And the G4's pathetic 1.3 GB/sec is killing it.
A deep unwavering belief is a sure sign you're missing something...
Go ahead, try to say something disparaging about Sony's Emotion Engine. But preface it with the statement that Sony has sold 40,000,000 PSX2 game consoles which feature the Emotion Engine, and also mention that Sony is selling about 2 million more every month. I've got two of these which my kids and their friends use, and they NEVER crash. What is your standard for success, by the way?
The idea that this will be a strictly middle-of-the-road processor is to ignore some important facts. AMD's and Intel's 64-bit options are primarily geared towards servers and workstations. Meanwhile IBM claims that their GPUL was engineered primarily for personal computers NOT servers. Thus Apple could become the first computer manufaturer who puts 64-bit processing power in the hands of the general population. If the average Joe relizes that the wave of the future (64-bit) is inevitable, he'll probably want to get on early. Plus, don't forget the Altivec support built into the chips as well as the new super-bus that they are working on with nVidia. Not only will Apple get a powerful processor, but they'll also get a pipeline capable of feeding it.
Well, a bit off topic, but...
:-) /zugedneb
I think that we should be thinking more and more on the power consumption of things in
general... On the environment, you know...
I wonder for how long "The_American_Way" will
hold...
It would be interesting if some law turned up,(I am from Europe, Sweden), that would make
some serious "restrictions" on the
power/performance phenomenon...
It would be the rebirth of elegant
engeneering...
Ouch. I just had a very nasty thought that you might be very Very wrong. Assuming Jobs is that insideous, I'd give it a slim chance. IBM brokers the deal between Sony and Apple to bring economies of scale to the 970 and. . .
... now realise that Sony is able to ship a number of exclusive titles, without making a loss on a console AND maintaining their premium on their titles.
Sony wants to sell less hardware and sell more games with a higher per title margin. Selling hardware at a loss is typical of the console market.
IBM supplies the goods, Sony & Co supplies the reference PS3 platform and games backing.
Apple continues building its brand name computing with the ability to run PS3 games. That gives Apple a MAJOR supplier of video games. People who own an Apple typically will be able to afford the various PS3 games.
-Tim
SPEC measures the performance of compiled code; the idea is that it is a benchmark of the combination CPU+OS+compiler.
This isn't perfect for everybody, but if your compiler can generate SIMD (like the Intel compiler can), you will benefit from it.
If your compiler doesn't generate SIMD code you'll get lower results, but so will all users who rely on the compiler.
"Mhz doesn't matter"
The MHz Myth that Apple talks about is not about trying to say that "Mhz doesn't matter", it's about the fact that MHz cannot be used as a direct comparison between architectures.
Of course MHz (brute force) matters. But what also matters is smart design.
I think showing a 333MHz G3 running faster than a 500MHz Pentium III, kinda proves the MHz Myth is just that. Bear in mind, that the G3 is not AltiVec equiped! So not getting a huge vectorized benefit here.
If you think that's impressive, look at the G4! I can't wait to see what CPU Apple actually unleashes next.
I'm astonished that there are actually people who think MHz is THE sole number to go by.
War crimes, torture, lies, illegal spying... Would someone give Bush a blowjob, already, so he can be impeached?
I can't find the link anymore, but last night I saw an article by Frank Soltis, the cheif scientist over the AS/400 unit. He basically laid out the evolution of the POWER achitecture (not the PowerPC) architecture and how it relates to the new 970 CPU. The first POWER cpu used by IBM was derived from their work with Moto and Apple, but it couldn't be used in the AS/400 line becuase of limitations in the chip. So IBM came up with Power2 (PowerPC AS). This exteneded the functionality of the chip to where it could be used in an AS/400 environment, but was no longer compatible with the PowerPC that Apple and Moto were selling. Then they added the POWER64 instruction set which made the chip faster for business and HPC applications, but drove it further away from the PowerPC platform. The POWER4 chip actuall includes 4 seperate instruction setts. POWER64, POWER32, PowerPC64 and PowerPC32. Adding Altivec and cutting out the second CPU core is what the 970 is. He didn't mention that there was really any overlap between it and the PS3 chip. POWER4 design was started in 96 so there may be some shared philosophy, but probably no real instruction matching between the two. He aslo said that the POWER5 (late next year) and POWER6 architectures would have some OS dependent accelerations put in them. He specifically mentioned that the chip would have an instruction for handling TCP streams instead of having to send several instructions to the CPU at once. And that these will be fully documented so that Linux/OSS can use them. POWER6 will extend that to specific DB2 and Domino calls to accelerate those apps.
The POWER4 and presumably the 970 will also have, a very very nice branch prediction scheme. The POWER4 uses a total of 3 branch predicters to the Intel P4s one. The 3rd table weighs the comparative performance of the first two tables to acheive the highest possible correct branch prediction.
In addition, the PowerPC architecture includes a static branch prediction bit for branching instructions, which allows the compiler to "hint" to the processor the likely branch, the x86 architecture has no equivalent feature.
In short, branch misprediction occurs less often with the POWER4 (and hopefully the 970) for the above reasons. In addition, the "tripling" of the G4 pipeline in the 970 is still shorter than Intel's 20 stage P4.
Spyky