Originally posted by wizard69
If they are able to run the internal MPX bus much faster than the external that would be nice also. The key to success here is certainly in the way that the interace to the three devices (core1, core2, and the bus interface unit) is handled.
MaxBus wouldn't be on board in this design. The onboard MaxBus connects the cores to an onboard memory controller, which this (speculative) design doesn't have.
Programmer's claim is based on the assumption? hope? that Freescale moved the inter-core communications (snoop/snarf, etc.) on die, and it's only using MaxBus to talk to the northbridge. If they didn't, then this design will still perform better (because of the bigger cache on die) and cost less.
Freescale's main problem as I see it isn't so much ambition as it is talent. Motorola management treated its senior CPU engineers poorly enough that they all jumped ship and went to Intel right around the release of the 7450. Motorola, and now Freescale, is limping along with the remaining crew. They seem to have gotten comfortable and experienced with this core by now, and if Freescale is able to reassert itself as both competitive and a good place to work then they'll be able to start attracting talent again. (The odds that they'll ever get their old team back are essentially negligible: Intel is a famously good company to work for.)
The fear I would have is that any clock rate increase in the core would quickly saturate the gains made in the FSB. This would probeally do well up to about 2.2 GHz, taking into account the much larger caches and general purpose work loads.
I've been saying this for a while now: The main reason Freescale has been slow with clock speed updates is that there's hardly any point. The CPU/bus clock ratio is already right near the maximum for balanced performance.
Once MaxBus goes on die, I think we'll be surprised at how well the e600 core scales. It will never threaten the P4 or Cell, but it should be able to acquit itself nicely. Freescale has spent a lot of time hand-tooling it to run very efficiently.
Hopefully Apple sees the Mini as an important part of their business going forward and understnads the need for SMP hardware in that level of equipment.
Speaking as one of the more vocal "headless Mac" naysayers, pre-MacWorld: If they don't, I will personally fly out to Cupertino and smack Jobs around until he does understand it. I haven't seen this level of interest in a Mac since... well, I don't know when. Even the iMac was mostly seen as energizing the core base and reviving the company.
The reality is that Apple could build a Mini for next year with PCI-Express Video on an e600 platform. That seems compelling right there, so it would appear that the life span of a 7448D would be tied to upgrades and usage outside of Apple.
On the other hand, depending on the exact implementation, the cost of dropping a dual-core 7448 into an existing G4 motherboard might be low enough to make it worthwhile even for only one or two upgrade cycles. That would also give Apple time to really nail the next-generation motherboard design, assuming that they use Freescale's 86xx CPUs.
I don't see why they wouldn't, actually, given that Freescale's performance/watt numbers look pretty damn good right now.