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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: SHADES on August 24, 2003, 11:37:55 PM

Title: What's a real G5 anyway?
Post by: SHADES on August 24, 2003, 11:37:55 PM
Let's talk about CPU's

Please correct me if I am wrong but I am certain that AMIGA used the PPC chips made by Motorola.
Now, next is the G3 CPUs. Apple also moved from PPC chips to G3 technology Altivec CPUs, umm, also made by Motorolla. Then G4.
What confuses me is that G5 arrived and is made by IBM.
So I guess my questions are:
1. Has Motorolla sold the technology to IBM
2. What does this mean for Motorolla
3. IF not sold, it must be completly different. (Altivec is a Motorolla (c) invention )
4. Ok No ALtivec in G5 so what is it? A new RISC chip?
5. Compatibility with previous G series cpu's

You get the drift. More of a what's going on questions and answers topic.

I'm not sure how accurate some of the questions are here, I haven't done much research, just a catch up.
Title: Re: What's a real G5 anyway?
Post by: iamaboringperson on August 24, 2003, 11:43:54 PM
Hi SHADES, lovely day! :-D

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Please correct me if I am wrong but I am certain that AMIGA used the PPC chips made by Motorola.
Well they.... did, but not as standard.

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Apple also moved from PPC chips to G3 technology Altivec CPUs,
G3 is still PowerPC.

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1. Has Motorolla sold the technology to IBM
More than 10 years ago Apple, IBM, Motorola, and a number of other companies formed what is(or was) known as the AIM aliance. Basically this means that they all worked to gether on the PowerPC project, and shared much of the IP.
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2. What does this mean for Motorolla
It means that they can continue making G5's
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3. IF not sold, it must be completly different. (Altivec is a Motorolla (c) invention )
Altivec is Mot's invention, but IBM can use it too.
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4. Ok No ALtivec in G5 so what is it? A new RISC chip?
Same old RISC chip with Altivec extensions
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5. Compatibility with previous G series cpu's
High. :-D

Title: Re: What's a real G5 anyway?
Post by: SHADES on August 25, 2003, 02:16:40 AM
Right! thanks, not such a boring person afterall :)

So this AIM alliance is still functioning?
I hope the IT is still being shared amoungst companies to try and form some sort of alternative to the Intel x86 domination.
A good idea as long as everyone continues to share.

Thanks for the info, off to look at the specs.
Title: Re: What's a real G5 anyway?
Post by: iamaboringperson on August 25, 2003, 02:19:47 AM
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Thanks for the info, off to look at the specs.

Here is a link that I hope will help :-)
http://www-3.ibm.com/chips/index.html (http://www-3.ibm.com/chips/index.html)
Title: Re: What's a real G5 anyway?
Post by: olegil on August 25, 2003, 06:32:09 AM
The CPU in the BlizzardPPC (for A1200) is a first or possibly second generation PowerPC.
The one in the CyberstormPPC (for A3000/A4000) is a second generation PowerPC.
The third generation was the PPC740, but the name "G3" kinda stuck and now applies to all CPUs that are more or less compatible with the 740. The 7400 was the G4, introducing Altivec. IBM has never used Altivec until now, but their POWER series (which is another derivation from the same basic theory behind PowerPC) has had a different SIMD (Single Instruction, Multiple Data) implementation. For their next "G3" they are looking at including an Altivec compatible SIMD unit, and they also use this on the so called "G5", which is a customised POWER4 cpu made for the desktop market.

The single, most confusing piece of all this is that non-technical people only look at the number after the G and think they know everything from that. But you really can't compare a PPC740 at 250MHz with a PPC750FX@800MHz or more. It just isn't fair.

It's almost like Intel changing the core of the Celeron from P2 to P3 then P4. You need to know not only what it's _called_, you need to know the excact core number/name and the frequency to really say anything specific...
Title: Re: What's a real G5 anyway?
Post by: DethKnight on August 25, 2003, 07:27:15 AM
Another link for the truly pedantic

http://arstechnica.com/cpu/03q1/ppc970/ppc970-0.html

includes such things as;

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When news of the 970 first hit the Web, there was considerable confusion about the status of the Altivec instruction set and its relationship to both Motorola and IBM. I'll go ahead and clear that up now, for anyone who's still confused. The SIMD instruction set known as "Altivec" was co-developed by both IBM and Motorola, so it's co-owned by both of them. Motorola has a trademark on the "Altivec" name, so in most of IBM's literature (but not all) the instruction set is referred to as VMX, presumably for "vector multimedia extensions." So VMX and Altivec are two different names for the same group of 162 vector instructions added to the PowerPC ISA.
Title: Re: What's a real G5 anyway?
Post by: minator on August 25, 2003, 10:32:04 AM
G5 is a scaled down POWER4 with Altivec thrown in.

Altivec came from the same 3 (I believe it was an Apple guy designed the architecture).
Motorola did the first implementation, IBM simply chose not to use it at that time.

The PowerPC ISA was a joint project by IBM, Motorola and Apple, but it's based on POWER which was around before.  The first implementation, the 601 (which shares a name with the first ever IBM computer BTW) was developed jointly, it partly reused parts from the Motorolas 88,000 series.

Since the G3 the chips have been developed independantly by the companies so a Motorola "G5" (i.e. the 8500) is a completely different chip from the IBM 970 (renamed by Apple as the "G5").

To confuse things further POWER are now PowerPC compatible...