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Motorola G5 - 2Ghz 64bit
Nerdkiller writes "
An article appeared on ZDnet with some information on the G5 chip expected in 2 years. It will be competing with the Intel Merced which is expected out around the same time. A full 64 bit 2 Ghz processor. The Intel Merced will be able to support 64 bit processing, however it must be run under emulation for 32bit code. The G5 requires no change in current code with exception to some low level OS stuff.
"
Every two years the speed of software halves.
So all this stuff makes not a damn bit of difference.
Now look - you've gone and made me grumpy.
Now if we could just get some additional, good, free, open-source operating systems ported to run on this chip, it would be even better.
LinuxPPC is there, and good; I've been very impressed by what it can do. But wouldn't we all like to see FreeBSD, or other Linux distributions ported to run (and run well) on PPC chips? And even better, now on the G5. I can just see the performance of a full 64-bit native OS running on that chip... *drool*
But then again, we have plenty of time before they come out to do the work!
---
Tim Wilde
Gimme 42 daemons!
There seems to be some misunderstanding on the PowerPC archetecture.
The PowerPC architecture is a instruction set definition written by Apple/IBM. It specifies a set of 32bit and 64bit instructions that PowerPC implementations must follow. 32bit implementations do not need to implement the 64bit instructions. (they are specified as optional in the specifications)
Under PowerPC, 32bit and 64bit code can be executed at the same time (no mode switching like x86).
All current PowerPC chips are only 32bit implemenations. It appears that the G5 will be the first 64bit PowerPC implementation.
It makes no sense ditching the 32 bit instructions because supporting them is
1) Not very expensive in the PowerPC archiecture (unlike Merced)
2) You can write faster programs by mixing the faster 32 bit instructions with the slower 64 bit instructions when needed.
3) Allows people to run existing and 64bit software transparently. (imagine 64bit modules on a 32bit database server)
Yes, AMD K6 has a RISC core underneath, and instructions are translated to what AMD calls the "R-ops", if my memory serves me right. AMD K6 has its roots in the NexGen Nx686, which was the successor to Nx586, the first x86 clone on the market which could compete with Pentium's performance.(it was a nice processor, but it flopped for several other reasons) The reason I'm telling this is that Nx586 had an assembler of its own, and theoretically could be programmed using its own RISC assembly language, bypassing the full x86 compatibility layer altogether.
Anything derived from the P6 core (Celeron, Pentium Pro, Pentium II/III) behaves pretty much the same way-x86 instructions are converted to RISC-like shorter ops, and executed by the core. I believe Intel calls these "micro-ops" rather than "R-ops" like AMD does-hence avoiding the "R-word" they don't like to use much...
Zigbee Central: A Zigbee weblog
The difference between an ``embedded processor'' and a ``general purpose processor'' is as much marketing as anything else
At one point, the StrongARM was being strongly promoted as a Network Computer (aka ``X-Terminal'') device. Note the announcement of 1997 of the Digital Network Appliance Design.
And note that it is the processor used in the Rebel/Sidewinder that Corel Computers used to hawk.
The point of all of this is that the CPU is clearly not so ``embedded'' that it would be inherently useless in a ``desktop'' role.
It ought to have been possible to build motherboards integrating a CPU, video chipset, and Ethernet that could retail for less than $150, and this could have brought us $300 computers a year or so ago, and provided slick little boxes to velcro to the sides of 17" monitors.
If I could have bought a StrongARM motherboard for $100, I probably would have built a machine by now.
But no motherboard leads to no systems. Note that exactly the same reasoning may be used with MIPS...
If you're not part of the solution, you're part of the precipitate.
They talk about Apple working on 266MHz SDRAM implementations, probably for future G4s and in anticipation of G5s.
Someone else mentioned that Alpha gets it's 200MHz/250MHz bus by multiplexing a 75MHz 256bit wide bus. I can imagine 8 64bit memory buses running at 100MHz, which is can be worked with as a single 800MHz 64bit bus. But that's a darned high wire count. More likely you'd get 8 32bit buses at 100MHz or even at 133MHz.
Excuse me if I don't make much sense, I'm speculating here =)
-AS
-AS
*Pikachu*
I'd actually believe that Motorola has no problem selling it's PPC and 68k CPUs in embedded systems, and it was only recently with the advent of $600 systems that the popularity of architectures and CPUs becomes an issue.
I mean Motorola sells a 68k CPU with every Palm and Visor out there. If they have an embedded processor in a cell phone, I'd think they would be selling more cell phones than PCs. Yes, PPC CPUs in computers would be more popular, but it wasn't necessarily the most profitable or intelligent thing to do; it would require that Motorola(or someone else) support AGP chipsets, PCI chipsets, memory chipsets, etc, for a single system to make a profit.
If you haven't noticed, Apple does this all by themselves. If you search IBM's website for PowerPC, you'll also see that they had PowerPC systems for sale since 1996 or something, but at $6,000 costs.
I can't imagine anyone just picking up the PowerPC platform until LinuxPPC stabilizes and matures, because I don't think anyone can compete with Apple on a design standpoint and no one can compete with Intel on a price standpoint.
Apple may be our only hope here =(
-AS
-AS
*Pikachu*
I forgot the url to the roadmap:m ap.pdf
http://www.mot.com/SPS/PowerPC/overview/newroad
No, not really. Despite the recent dabblings with the Alpha, the focus of the FreeBSD group has always been on getting it to work well on Intel hardware. Look to the other BSDs for PowerPC support:
"The invisible and the non-existent look very much alike." -- Delos B. McKown
If you look at the various architectures on which Linux runs, there are three varieties, in general:
There are a boatload of IA-32-based Linux systems.
There are a fair number of such systems.
PPC is hard to assess; it is easy to buy a PPC Mac from Apple, but fairly difficult to buy just a motherboard.
If PPC motherboards were readily available, PPC would be vastly more popular...
If you're not part of the solution, you're part of the precipitate.
I'm not sure how fast a 2 GHz CPU will seem unless we start seeing some really fast RAM and BUSes. Right now the fastest bus I've seen is 133 MHz, and the fastest large scale RAM on the horizon is still RAMBUS. Neither of these will allow a 2 GHz processor to run anywhere near it's full potential. Even with lots of cache you would only approach some upper bound that wouldn't be anywhere as high as 2GHz.
There needs to be some other advances, other then jacking up the CPU speed, before processors like this become useful. Maybe it'll be a new RAM or BUS design (RF anyone?), or a new way of dealing with code internal to the CPU to make memory more effecient then using it for cache. Which ever it's time to start looking at them.
The G4, with the AltiVec additions, makes a fantastic DSP development platform. In case you didn't realize, Altivec supposedly completes a multiply-accumulate every clock cycle minumum (It can actually do 4 per clock cycle because of the SIMD architecture). Doing a single-cycle MAC is almost the definition of a DSP. But to really take good advantage of the DSP aspect, you need an honest-to-goodness RTOS.
Now last I looked, TI's 'C6x architecture was headed that way with speed and scalability, but no one is ever going to write or port a general purpose OS (ie, Linux, Windoze, MacOS, Be) for/to that chip.
The G4, however, already runs at least MacOS and Linux. Unfortunately, neither of these are real-time systems. (Has RTLinux been ported to PPC? A great project, if not!) And it's too bad that the situation with Be prevents them from taking advantage of this great chip.
Anyway, I guess my point is just that having a hosted (versus embedded) DSP development system would be just the coolest, and that the G4 makes this possible for wont of a RTOS.
I have not seen anything yet that state explicitly that the G5 will have AltiVec on it. God, I hope so, though.
(drool-mode off)