I've always wondered, say we took the original 250nm G4 (7400 chip) and made it on todays 65nm process, what sort of speeds would it likely run at?
Faster, no doubt, but Moto's problem was that they had a very sophisticated and efficient frontside bus (Maxbus) that would have needed a complete redesign to get past 200 mHz. It had complex circuitry that did cache snooping and clever controlling of commands on the bus. They would have to have made a simpler bus in order to get the speed needed for today's streaming data rates. If they could have done that, then the Altivec unit, properly programmed, could have almost run at the bandwidth. As it is, the Altivec unit sits waiting for the next vector most of the time. It's still much faster than doing the arithmetic in the scalar units, but both are hamstrung by the 200 mHz memory bus. Compare the IBM G5's 1000 mHz Elastic Bus, and Intel's 1333 mHz bus on the Mac Pro. The G5 also had two independent buses, one for each processor in the dual configuration, and each of those had two separate buses, one for each direction, all running at 1 gHz.
that is true, i remember seeing a document once, that was either simulated or perhaps executed entirely from cache that demonstrated the power of altivec when there was no wait for data to come over the bus and it absolutely kicked ass in compute power.
Interestingly, AMD just announced SSE5 instruction sets for 2009 - and the word over at ars is that this brings the SIMD power to 'almost' altivec levels.
Its a sad fact that the much derided G4 chip was an absolute monster in its time (1999) and has taken over 10 years for competitors architechtures to catch up.
I wonder with Barcelona coming out and SSE5 if it would make sense for Apple to use AMD (Barcelona) in the Mac Pro.
I'm not anti-Intel. I think they're doing great. But I think Apple would be wise to keep their options open chip wise and Barcelona may be the chip that AMD has that can compete with Intel.
I wonder with Barcelona coming out and SSE5 if it would make sense for Apple to use AMD (Barcelona) in the Mac Pro.
I'm not anti-Intel. I think they're doing great. But I think Apple would be wise to keep their options open chip wise and Barcelona may be the chip that AMD has that can compete with Intel.
It looks like a competitive chip, but if Apple has business reasons for staying with Intel, then they'll stay. Particularly if they get a better discount or more support engineers if all their machines use Intel chips or something like that.
It looks like a competitive chip, but if Apple has business reasons for staying with Intel, then they'll stay. Particularly if they get a better discount or more support engineers if all their machines use Intel chips or something like that.
Comments
http://www.engadget.com/2007/01/04/i...around-the-co/
I've always wondered, say we took the original 250nm G4 (7400 chip) and made it on todays 65nm process, what sort of speeds would it likely run at?
Faster, no doubt, but Moto's problem was that they had a very sophisticated and efficient frontside bus (Maxbus) that would have needed a complete redesign to get past 200 mHz. It had complex circuitry that did cache snooping and clever controlling of commands on the bus. They would have to have made a simpler bus in order to get the speed needed for today's streaming data rates. If they could have done that, then the Altivec unit, properly programmed, could have almost run at the bandwidth. As it is, the Altivec unit sits waiting for the next vector most of the time. It's still much faster than doing the arithmetic in the scalar units, but both are hamstrung by the 200 mHz memory bus. Compare the IBM G5's 1000 mHz Elastic Bus, and Intel's 1333 mHz bus on the Mac Pro. The G5 also had two independent buses, one for each processor in the dual configuration, and each of those had two separate buses, one for each direction, all running at 1 gHz.
Interestingly, AMD just announced SSE5 instruction sets for 2009 - and the word over at ars is that this brings the SIMD power to 'almost' altivec levels.
Its a sad fact that the much derided G4 chip was an absolute monster in its time (1999) and has taken over 10 years for competitors architechtures to catch up.
Shame it died in the hands of the incompetant.
I'm not anti-Intel. I think they're doing great. But I think Apple would be wise to keep their options open chip wise and Barcelona may be the chip that AMD has that can compete with Intel.
I wonder with Barcelona coming out and SSE5 if it would make sense for Apple to use AMD (Barcelona) in the Mac Pro.
I'm not anti-Intel. I think they're doing great. But I think Apple would be wise to keep their options open chip wise and Barcelona may be the chip that AMD has that can compete with Intel.
It looks like a competitive chip, but if Apple has business reasons for staying with Intel, then they'll stay. Particularly if they get a better discount or more support engineers if all their machines use Intel chips or something like that.
It looks like a competitive chip, but if Apple has business reasons for staying with Intel, then they'll stay. Particularly if they get a better discount or more support engineers if all their machines use Intel chips or something like that.
That is what the AMD vs intel law suit is about.