Re: Vaporware!
Originally posted by peter2002
No main memory RAM exists that does 6.4GB/sec. The fastest RAM is 1066 RDRAM which clocks out at 4.1 GB/sec. Next October 2003, Rambus is coming out with 1333 RDRAM which will max out at 5.2 GB/sec.
You won't see anything faster until mid 2004. You are dreaming if you think Apple will have the Power4 in the PowerMac in Jan. 2003. All you will see is a faster G4 that Motorola will call G5 clocking at best 1.6GHz, built w/ 130NM tech, with a 512 cache, and maybe at best a (real) 333 DDR front side bus. Not the overclocked crap Apple is pushing now. Motorola is too broke and losing too much money to make anything faster.
And the Power4 is incompatible with AltiVec based software. Developers won't spend millions to rewrite their software to run on the unproven Power4.
Peter
Ok just to correct a few facts. Firstly RDRAM offers less bandwidth than DDR RAM. The only reason RDRAM shows as higher is because currently you can only buy it as a dual channel offering, which effectively doubles the bandwidth. The real bandwidth of RDRAM 1066 is only ~2.1 GB/s. Dual channel DDR RAM can reach 4.2 GB/s with DDR-266, 5.4GB/s with DDR-333 and 6.4 GB/s with DDR-400. Offerings already exist for dual-channel DDR-400 memory as well.
Second the MPX bus will never be a DDR bus. Not ever. Technically it's too much trouble and doing things which are technically troubling costs money, which Motorola by your own words can't afford to spend.
Motorola is already switching their G5s to on-chip memory controllers and RapidIO and assuming they were to release a next generation system for Apple they would do the same.
Third Apple does not sell overclocked systems. Anybody who says otherwise is simply ignorant.
Finally you are correct the POWER4 won't appear in Macs but you are wrong in that the POWER4 isn't an unproven technology.
Additionally IBM has already come on the record as stating they are developing a POWER4 derivative with a SIMD unit. It won't be altivec, which is Motorola's implementation of that instruction set, but Apple isn't planning on using anything in their future chips (at least for the near term) that doesn't retain altivec compatibility.