Slashdot Mirror
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..."
Depends....where do you want to go today?
Cheers,
Ian
"In fact, some are suggesting the PPC 970 chip might be closely related to the PS3's 'Cell' processor..."
Even though it's really doubtful, it'd be extremely cool to see a PS3 emulator on the mac if the processors are that closely related.
I remember running Mac OS 6.0.5 on my Atari ST. Because it had the same processor, it didn't need much to make it run.
Oh well, I can at least dream, can't I?
Not that hot NOW! They will have a lot of competition in that space with Opteron/Clawhammer, and the new Sparcs.
Still, glad to see something other than incremental progress.
The law is a weapon of the government, not a protection for the likes of you. Surely you understand that.
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...
I mean... it's great news that Apple won't have to rely on Motorolla's decidedly passive desktop chip development strategy anymore...
But man. First off, this kills any possibility of a big surprise hit. Second, this dooms apple sales for the next year or so... who wants to buy a stagnating desktop model when the next edition has so much promise?
Then again, Apple's desktop offerings have been a little stagnant anyway... most people probably won't want to play the waiting game for as long as it'll take for these to come out.
I just hope that by the time they do, they're worth it.
" In fact, some are suggesting the PPC 970 chip might be closely related to the PS3's 'Cell' processor...""
Ah, so it runs on vapor instead of smoke?
*wonders if anybody'll get that.*
A couple of points to throw water on this:
Apples are certainly wonderful machines, and Windows certainly is icky most of the time, but be prepared to back up any benchmark statements with actual benchmarks.
Also, PowerPC and Intel/AMD are two different types of processing, so they can't really even be compared.
Um, no.
All general-purpose microprocessors perform certain basic tasks upon which everything else is built - integer and FP math, memory access, and control flow operations. Processors take different approaches in how they implement these functions, but the interfaces presented to programmers - even assembly programmers - are very similar [and yes, I've done assembly on multiple platforms].
You can also completely ignore architecture and take test programs that you think are representative of the kinds of tasks found in different types of application, compile them for both platforms, and measure how long it takes to do the same amount of work on each machine. This is the _foundation_ of benchmarking.
If the machines were completely different, you wouldn't be able to do the same tasks on them!
The PowerPC 970 triples the length of the PowerPC pipeline
This will give it the same issues the P4 has. Namely a large penalty for branch mispredicts, etc. Instructions per clock will decrease.
OTOH, they should be able to crank the speed!
The law is a weapon of the government, not a protection for the likes of you. Surely you understand that.
... 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...
"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.
> Instructions per clock will decrease.
.09 process shows me that this 970 chip has legs. Another thing... IBM has *always* been conservative about what not-quite-ready chips will do as far as clock, and benchmarks. I expect "Real World" [no relation to Peter Gabriel] performance to be quite good. [although I expect Peter Gabriel's performances to be fantastic =)]
Actually, IPC is *increased* from the current G4. It will now fetch 8 instructions per clock, and retire 5 per clock.
The current G4 IIRC fetches either 3 or 4 per clock. I have no idea how many it can retire at once.
This coupled with a quick move to a
Blocklevel: Practical Information Architecture
Does it?
The eetimes story linked at the top says it's an 8-stage pipe. That doesn't mean any more or less than the extreme tech statement that the new pipe is triple the length (which would be 21, the current pipe is 7) since we haven't seen any actual reference docs from IBM.
Can anybody who was at the Microprocessor Forum give us more info?
Don Negro
Perl 6 will give you the big knob. -- Larry Wall
I have no idea who you are, Mononoke, but I'd wager $1000 that Hannibal Stokes knows more about chip architecture than you do. The PPC 970 will have a hard fight (both in marketing and benchmarks) against the 4+GHz x86 chips also due a year from now.
p.s. How the heck did that get rated as Insightful? I'm as rabid a Mac addict as any of you, but it's just plain wrong to mod someone up for spouting false evangelism.
Once you move beyond a 4.5billion, into the realm of 18.5 (two orders of magnitude past trillion), you can address anything for the forseable future (since you can count each year until the heatdeath of the universe this way, for example).
For vector operations, 64bit words make for some fast math operations, since you can pack more 32-bit integer components into each bus transfer.
For floating point, it means you have greater precision in hardware (allowing things like real physics and shapes to be modelled without noticable issues caused by subtle number creep). Since most systems use IEE-784 (64bit double precision floating point), it means a speedup to that software since you're not working with it as 2 32-bit operations.
In terms of storage space, it means you can address more than 2,199,023,255,552 bytes (~2 terabytes) of disk space (assuming a 512-byte sector). This is important for people with big RAID arrays today, and people with ludicrously big Maxtor drives 3-4 years from now.
For RAM, it means you don't have to worry about your server topping out at 4 gigabytes of RAM. It also means that your VM space has no effective limitation for the forseable future (very useful for people working on large projects, trying memory-intensive algorithmic approachs to traditionally NP-hard problems, or distributed computing problems).
I'm sure I missed a lot of the benefits even with this list. As you can see, 64-bit is not just a number game. It is 32 orders of magnitude larger than 2^32, meaning our grandchildren will probably still be using 64bit machines with no limitions being apparent (unlike 16-bit to 32-bit, which only moved from 65k to 4.5 billion in terms of addressable amounts of something).
--
Internet Explorer (n): Another bug -- that is, a feature that can't be turned off -- in Windows.
Actually, the DDR thing is a little misguided. The real reason DDR had no effect was because the 2.1 GB of memory bandwidth was feeding into 1.3 GB/sec of processor bus bandwidth.
A deep unwavering belief is a sure sign you're missing something...
Contrary to some of the opinions presented recently it is just fine for Apple to use the 970 and be behind the curve with respect to typical performance. Sure there are specialized apps that can leverage a RISC architecture to outperform x86 or leverage Altivec to outperform SSE, but that is a small minority. Typical performance lags behind PC a little but we are in a situation where PCs and Macs have more performance than most people actually use. Most folks out there in the real world will get along very nicely with a 1GHz PC or a 800MHz Mac. Very few people need 2.xGHz machines, and only a few more have enough disposable income to buy those machines for Quake FPS pissing contests :).
The real Apple problem is that the gap between typical PC and typical Mac performance is starting to grow beyond the range that has historically shown to be viable. Not a problem today, standard dual CPUs counter this to a degree, but it's likely to be a problem in a year or two. While the 970 may only perform like a 3GHz P4 (SPEC), lag whatever Intel/AMD has in a year or two, it will be close enough. Apple will be back to a point where the typical performance gap is small enough. Apple has sold tens of millions of Macs that lagged PC counterparts in performance. They know that their customers are more interested in ease of use. Performance wise close-enough is all they need.
"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?
PPC chips can only work on one swing of the computing "cycle", not on the up and down like an Athlon can for example
It's called positive and negative edge triggering. It's not a new technology either. I was dealing with it in the 80's at the discrete logic level.
AGP 2x uses this and 4x uses positive, negative, high and low triggering. Certain UDMA modes make use of this clocking technique also.
Your argument doesn't hold water.
His arguement DOES hold water. PPC CPU's DO outperform Intel x86 CPU's by a good margin when compared clock for clock (showing the MHz Myth for what it is). Especially the G4 and boy when AltiVec can and is exploited... Wow. There IS more to CPU design than smaller die and deeper piplining for higher MHz.
As far as I can tell, Apple seem to be in a position where they have to make the best of what they can get, due to Motorolla dropping the ball pretty baddly.
I hope IBM comes to their rescue. How ironic.
War crimes, torture, lies, illegal spying... Would someone give Bush a blowjob, already, so he can be impeached?
http://www.heise.de/ct/english/02/05/182/
j pg)
. ht ml
SPEC benchmarks for the G4 processors. (Not a synthetic benchmark issued by Apple, but by an unbiased third party, SPEC)
G4 1 GHz SPECs at 306 integer 187 floating-point
Interestingly, the 1 GHz G4 was almost neck-and-neck with a 1 GHz PIII (http://www.heise.de/ct/english/02/05/182/qpic02.
http://www.spec.org/osg/cpu2000/results/cpu2000
A large archive of SPEC results for many CPUs, including x86.
A few choice results:
1.2 GHz Athlon (Ancient by today's standards) - 443 integer, 387 FP
Athlon XP 1700+ on an Epox EP-8KHA (Happens to be my mobo - Slowst Athlon XP listed for this mobo):
633 integer, 561 FP
Dell Precision Workstation 330, 1.3 GHz P4 - 474 integer, 502 FP (The P4 doesn't seem to be taking too much of a branch misprediction hit here)
So in the case of G4s, while they may be a bit more efficient MHz for MHz (And the P3 vs. G4 benchmarks so that this isn't even necessarily the case), the fact that they're so far behind on the clock speed curve hurts them badly.
If you want to see a good example of MHz not being everything, check out the benchmarks of Alpha systems - The 750 MHz ones chew even 1.2 GHz Athlons for lunch. But don't look at Apple...
Also interesting in the case of the SPEC benchmarks run by Heise - MS C pays a 10-15% performance hit over GCC in the SPEC benchmarks.
retrorocket.o not found, launch anyway?