New chip?? Clear me out on that one

MacLegacy

Unemployed Student!
Do the new powermacs really have a new chip or is it the same chip ? I'm lost in all this! I thought it kept the same chip though

This is no whining, just a simple question
 
The macs use a dual-G4 setup, so nothing to ground-breaking there, however they now include a new chip to manage the processes and system bus, as well as ethernet and firewire. So, no its not a new type of processor, but a new chip for balancing the load between the 2 processors.
 
thx

so that new chip doesn't do much to improve performance..
it's not like 7450 compared to 7470 (if those are the good numbers)
 
The new PowerMacs, as far as is known, contain the same PPC 7455 processors than the recent Quicksilvers. The PowerPC 7470 was rumoured, first my mosr.com and The Register. It was all a bit muddled, as they also said at that point that the 7500 would then replace the 7470. People started to muse whether the 7500 would be a real G5 or just another G4, while the 85xx line would be the G5. And nowadays the G5 seems to be something like a unicorn. The only _sure_ thing we know is that Apple stated 'the G4 has quite a bit of life in it'.

What if rumours about quad processor machines are true? If Mac OS X 10.2 (or an update) can handle those processors well, we could see a dual/dual/quad lineup after six months (MWSF or MWTK), which would finally be replaced by a next-generation-processor in Summer/Autumn 2003. And I don't think _that_ would be bad.
 
Originally posted by fryke
What if rumours about quad processor machines are true? If Mac OS X 10.2 (or an update) can handle those processors well, we could see a dual/dual/quad lineup after six months (MWSF or MWTK), which would finally be replaced by a next-generation-processor in Summer/Autumn 2003. And I don't think _that_ would be bad.

Quad processors would be overkill. The top of the line Dual PowerMac is $5000, I shudder to think about what a Quad PowerMac would cost.

Also, who would benefit from such setup? Programmers and graphic designers? I don't think so. Sun and SGI don't even offer Quad setups. I'm guessing because there's not really a market for such a machine at the workstation level.

Since I started running 10.2, I've been less concerned about Apple's G4 quandary. I think Jaguar will certainly breath new life into both new and old Macs give Apple ample time to get their sh*t together.

I just hope when the G5 does debut, it's one hell of a processor, but for the mean time, maybe the G4 does have a little bit of life left in it. Especially thanks to Jaguar.
 
I meant that the Quad would cost the same amount as the current top-end.

As I've never worked on a quad processor PowerMac with OS X 10.3, I can't really say what it would -be- like. But it would surely find some buyers, I guess. My secret wish is still to have a TiBook with dual processors, turning one off on the road...
 
Originally posted by azosx

Also, who would benefit from such setup? Programmers and graphic designers? I don't think so. Sun and SGI don't even offer Quad setups. I'm guessing because there's not really a market for such a machine at the workstation level.

Uhm...I have three Quad SGIs. An old Onyx RE2 QUad R6k, An Onyx2 IR3 Deskside with Quad R10K at work and an Visual Workstation 540 with Quad XEON 500.

The Workstation line (currently O2+, Octane2 and Fuel) does not offer a Quad setup since it wouldn't make sense in SGI workstation machines and it wouldn't fit into those small casings (those MIPS tend to get hot). The workstations also don't need this power, they are designed for different usage.
The Quad setup from SGI starts with the Origin desksides, which are still looked at as workstations. Sure, you're statement is right that SGI workstations just don't need a Quad setup. They would be too expensive. A current Origin Deskside starts at around 70.000 dollars (singe CPU), while you get a double CPU Octane 2 for half of the cost!!!
Quad machines are bit different that dual. Balancing the load on a dual board is no problem, but as soon as a third or fourth processor is present, you have to add some things. First, you need voltage balancer for the processors (common even in single CPU servers). Another thing to consider when building Quad boards is the internal bandwith, the XBar like design of the new PowerMac might help here.
Also, one should not forget that the speed gain from a Quad system is not as big as from a dual system compared to a single system when it comes to daily work. I am working in the SGI branche for half a year now and sadly had to learn how hard it is to write an application which properly scales over four CPUs!!!

If you take a look at current Quad CPU systems, you notice that all of them come in deskside chassis, because you just can't cram them into towers, it would get too damn hot. Take a look at the passive cooler of the G4!!! Now add another one of that, another 9 inch cooler....where???

They would either have to redesign the chassis to an expensive deskside or go to a different approach called multi-chip module. IBMs makes some pretty MCMs which are used in the Cray SV2, but I red they are working on MCMs for customer machines.

Last but not least, Quad CPU machines need lots of power. Sure, the G4 is not that hungry when it comes to power consumption, but you would need a better (and thus hotter) power supply.

At the moment, Apple can't just stick four G4s in a current casing, it just wouldn't work. If you take a look at the video which floats around the net about a Quad G4, the case is nearly VW 540-sized, nearly deskside size.

If Apple wants to release Quad machines (which I hope) they would need to redesign the complete PowerMac package.

Before going Quad, they should go 64 Bit, it has a bigger impact (allthough applications have to be rewritten and recompiled to advantage from the bigger word size).
 
Originally posted by MacLegacy
thx

so that new chip doesn't do much to improve performance..
it's not like 7450 compared to 7470 (if those are the good numbers)

I personally am impressed with the Apple engineering for this bus chip. It handles any speed memory with any speed microprocessor bus speed. This means they can plop in a 7470 or any other processor without worry about matching bus speeds like they do on the Athlon systems I build. I had problems for months trying to get Northbridge and Southbridge systems to work properly. It took them a few months to get it right. When they do come out with a 7470, lookout, as it should be one awesome chip. At least until the 64-bit PowerPC comes out.:) Well we know where the problems lie with new faster computers .... Motorola. Apple engineers probably had to wait around for the 1.25 GHz.:rolleyes:
 
If you check Motorolas information pages about the MPC7xxx processors, you may see that there _is_ no MPC7470 processor available. Well, there's also no MPC7455 running at 1.25 GHz to be seen, but it just seems to me like the whole processor was only 'rumoured'. Maybe even Motorola saw that the next processor they should release would have to be a real G5, something that brings in another dimension instead of a few more MHz (at the cost of a longer pipeline with more stages).

Guess we'll see in March 2003. G5 (MPC75xx)? IBM PowerPC (derived from Power4)? Something even cooler?

Whatever, I want a TiBook running at above 1 GHz, so I can at least say my old one had half the MHz. ;)
 
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