IBM's PPC750FX

[Mr. MacPhisto]

Can IBM's PPC 750FX be updated for consumer end Macs? I was looking at IBM's site and found specs on the chip, the one that is supposedly in the iBooks, and found that it can go up to 1GHZ and can support a 200MHZ FSB. With some updates and an Altivec engine added, this chip would surpass the G4. Even the G4 is really a good chip, its just that it bottlenecks due to the slow bus speed and weak DDR memory, even on the new machines. At 200MHZ the FSB could be manipulated to further increase speed and data transfer - just like Intel's 533MHZ FSB is really only a 133 that has been, essentially, multiplied by a factor of four. I'm familiar with some of IBM's technology, and I know they can push the FSB up to 600-800MHZ for the 750 - but will Apple ask them to?

 

[Mr. MacPhisto]

Here's the link to a PDF overview of the 750FX:

http://www-3.ibm.com/chips/techlib/techlib.nsf/techdocs/2FF4861D6755A6CA87256BB1006B1DE6

 

[macphoria]

I know people say G3 with AltiVec is G4. But I think the way IBM constantly pushed G3 forward, if they added SIMD function to their own G3 it will definitely outperform Motorola's G4. And I sincerely hope they do this at some point. iBook with IBM G3 and SIMD/AltiVec would rock.

 

[Catfish_Man]

Originally posted by macphoria
I know people say G3 with AltiVec is G4. But I think the way IBM constantly pushed G3 forward, if they added SIMD function to their own G3 it will definitely outperform Motorola's G4. And I sincerely hope they do this at some point. iBook with IBM G3 and SIMD/AltiVec would rock.

It would have a higher MHz (but less efficient) bus, and be made on a less advanced manufacturing process (and would have worse Altivec if it used the PPC970 scheme, which is like the old MPC7400/7410 chips).

Here's a chart showing the differences (750 is original G3, 7400 is original G4, 7457 is the very newest .13 micron G4 coming out this fall. FPU means floating point unit, the 604 style FPU is more advanced than the G3 one, and may be what the 750FX uses. AV is Altivec. The lower MHz number is for the bus. The 750's and 7400's L2 caches are off chip. The MPX bus is faster at the same MHz than the 60x bus)

750       750FX            7400          7457
G3 FPU    Enh. G3 FPU     604 FPU       604 FPU
No AV      No AV           Old AV        New AV
700MHz    1GHz            500MHz       >1.3GHz
66MHz      200MHz         100MHz       167MHz
.25u   .13u 6 layer SOI   .25u    .13u 8 layer SOI
1MB L2    512k L2         2MB L2       512k L2
no L3       no L3           no L3         2MB L3
60x bus    60x bus         MPX bus        MPX bus

Basically, the 750FX came out sooner and has a higher MHz bus, but is otherwise inferior to a new G4 in performance. It seems like it would be easier to boost the bus speed of the 7457 (Apple went to 167MHz before Moto announced it, they may do the same with 200MHz) than to add Altivec and boost the clock speed of the 750FX. Power consumption is slightly lower for the 750FX than the 7457 (3.6 watts @ 800MHz vs. 7.5 watts @ 1000MHz), but would be increased by adding the L3 cache, MPX bus support, and Altivec of the 7457.

 

[bousozoku]

Well, actually, the G4 FPU is only part of the 604(e) FP unit. There wasn't room for the whole thing because of AltiVec. It's better than the G3s FP unit, but worse than the 604(e) unit.

 

[Mr. MacPhisto]

I'm not too terribly sure the Motorola design is all that superior. Besides, part of the reason I even brought this up is because of Motorola's apparent lack of motivation in innovating or upgrading computing (non-embedded) chips. When the G4 was released it was a great chip for the time, but Moto hasn't done much since. Not only that, but their pricing makes the machines more expensive. A top of the line PPC 970 (1.8) will be less expensive than a 1.42, 1.25, or 1 GHZ G4 chip - mainly because of IBM's ability to streamline and distribute cost better. IBM can make superior chips, and make them less expensive. I think they could work on the 750 or create a next generation (760) that could blow away the G4. With the way that Moto has screwed around with Apple, I think it would be wise to break current ties amicably (Moto wouldn't mind, in all likelihood) and go with the manufacturing who can provide better tech and cheaper prices - hopefully bringing your machines in line with PC prices and making them the clearly superior product.

 

[ftaok]

Originally posted by Mr. MacPhisto
Not only that, but their pricing makes the machines more expensive. A top of the line PPC 970 (1.8) will be less expensive than a 1.42, 1.25, or 1 GHZ G4 chip - mainly because of IBM's ability to streamline and distribute cost better.

Has anyone seen pricing info for the PPC970? Motorola has announced the price for 7457s (and 7447s) and they seem very reasonable to me. They quote prices for the 7457-1Ghz @ $189. That's a lot cheaper than the 1Ghz 7455s, which were in the $300 range.

Besides, there's the added cost savings in that Apple doesn't have to change any of their motherboards, etc.

 

[Macpoops]

I personally feel much more secure with IBM handling chip design. I also feel that if Apple would shift entirely to IBM that would not be a bad thing. It would be better then Moto. The reason i say that is Moto doesn't really use the chips they make. They are a chip maker they don't sell the computers that their chips are in. Therefore, why should they care they still get their money when the push a chip out the door? They have little incentive for advancing their chip design

IBM has built in incentive. They use the chips they make so not only do they make money selling the chips but they make money selling the computers with the chips in it. They make double the money on the same investment. Their target computer market, servers and workstations, is very competative. They can't afford to not have the latest and greatest in that business, and they develop and build the latest and greatest chips in house.

Luckily for Apple they have simlar requirements to IBM but target a slightly different market then IBM. This creates a Win-Win situation that Apple hasn't had since Moto was making Mac clones.

Long live, The Apple-IBM relationship. It has been much more promising then the Apple-Moto relationship left over after the AIM consorsium. Maybe the AIM consorsium could heat up again only this time IBM will be making the chips for computers and Moto could be making the hardware for an Apple Cell phone. That in my opinion is the only real department where Moto makes a killing, Although i love my Nokia.

Sorry for his being a little of topic, but sometimes people just have to rant every now and then.

 

[macphoria]

-----I personally feel much more secure with
-----IBM handling chip design.

Yes indeed. Remember the whole charade with G4 Power Macs, when Apple had to delay shipping because Motorola couldn't deliver enough chips on time? But that is small part of the whole issue.

As Macpoops mentioned, IBM develops processors and implement them in their computers. Motorola does not specialize in computers. Motorola has done a decent job (I say decent because even though their recent G4 processors are terrific, they took forever to arrive at that stage) but IBM has always been reliable and innovative force in processor development. Just look at Power4, Power5, 970 and especially G3. G3 does not quite match up to G4 due to lack of SIMD/AltiVec, but Sahara G3 can still hold its own in its arena and even challenges G4 in others.

That just shows how processor savy IBM is and it makes much more sense for Apple to go with IBM than Motorola. And I stick to my original assessment that if IBM ever developed G3 with SIMD, it will outperform G4 by Motorola.

Yes this is some kind of tirade but I'm sick and tired of Motorola and how it held back Apple for ages. It is time for change and I only hope IBM 970 does not disappoint, and it probably will not.

 

[The Shadow]

Time is the age old enemy.