holland@mips.csc.ti.com (Fred Hollander) (12/06/88)
I heard that there is a 68030 replacement for the Mac II that runs at 33MHz for about $1000. First of all, how can the processor run faster than the rest of the motherboard? Second, how can they supply this at half the price Apple charges for the II->IIx upgrade which is only 16MHz. Was I just misinformed? Does anyone have more details or experience with this? Thanks, Fred Hollander Computer Science Center Texas Instruments, Inc. holland%ti-csl@csnet-rela The above statements are my own and not representative of Texas Instruments.
ecs175f037@deneb.ucdavis.edu (Greg DeMichillie) (12/07/88)
In article <65023@ti-csl.CSNET> holland@mips.csc.ti.com (Fred Hollander) writes: >I heard that there is a 68030 replacement for the Mac II that runs at 33MHz >for about $1000. First of all, how can the processor run faster than the >rest of the motherboard? It's been a while since I had computer architecture, so somebody correct me if I f**k this up... The processor would have to have several wait states for each Nu-Bus access since the bus is only clocked at 10MHz :-( So, some operations will certainly be much faster with the upgrade, don't expect everything to suddenly be twice as fast until Apple upgrade the Nu-Bux to operate at higher clock speeds (a la Steve Jobs' NeXT) >Thanks, > >Fred Hollander To quote Alf --- "No problem..." ----- Greg DeMichillie Apple Student Rep - UC Davis lgdemichillie@ucdavis.edu AppleLink: ST0178 Disclaimer: If you've seen one disclaimer, you've seen them all.
rang@cpsin3.cps.msu.edu (Anton Rang) (12/07/88)
In article <3356@ucdavis.ucdavis.edu>, Greg DeMichillie (lgdemichilie@deneb.ucdavis.edu) writes: >In article <65023@ti-csl.CSNET> holland@mips.csc.ti.com (Fred Hollander) writes: >>I heard that there is a 68030 replacement for the Mac II that runs at 33MHz >>for about $1000. First of all, how can the processor run faster than the >>rest of the motherboard? >The processor would have to have several wait states for each Nu-Bus access >since the bus is only clocked at 10MHz :-( The 68030 replacement must be on a separate board, I would guess. If it has a reasonably large cache (say, even 8-16K) there wouldn't be too many NuBus accesses (hopefully). There would indeed be several wait states for NuBus access, but this wouldn't occur that often. >So, some operations will certainly be much faster with the upgrade, don't >expect everything to suddenly be twice as fast until Apple upgrade the Nu-Bus >to operate at higher clock speeds (a la Steve Jobs' NeXT) Of course, the NuBus standard is 10MHz; so no standard NuBus cards would work with one running at a higher clock speed. The cache ought to give pretty good performance (remember, there are lots of large computers with slow memory). A graphics coprocessor (to reduce the amount of cycles spent waiting for video memory updates) would help a lot, too. Anyone for designing a custom QuickDraw chip? (Or a microcoded Display PostScript interpreter, even? :-) Anton +---------------------------+------------------------+----------------------+ | Anton Rang (grad student) | "VMS Forever!" | "Do worry...be SAD!" | | Michigan State University | rang@cpswh.cps.msu.edu | | +---------------------------+------------------------+----------------------+