Doesn't ram speed, ie. 70ns, 60ns, 10ns, have an effect on system bus speed capabilities?
Jeff Walther wrote: > At 19:05 -0500 11/09/2002, J J wrote: > Jeff Walther wrote: > > >>"It's moot with the G4/800 anyway. You can't > >>adjust the bus speed > >>without soldering to replace the oscillator. > >> > > >So, are you saying that the new G4 800 will let > >our buses go say 100Mhz (maybe). Or maybe a better > >question would be - How fast will the bus be after > >installing a G4 800 processor in it? > > The Sonnet G4/800 is set to run with a 50 MHz bus. That is how it > gets an 800 MHz CPU speed. The MPC7455 chip (G4 chip) has a maximum > bus multiplier of 16X. So 16 X 50 MHz = 800 MHz. > > If one could easily adjust the bus speed, one might get that up > higher. For example, 55 MHz X 16 = 880 MHz. However, who knows if > the MPC7455 will tolerate running at speeds higher than 800 MHz? > There was a news item on XLR8yourmac.com in which a fellow claimed to > have done a 60 MHz X 16 = 960 MHz with the Sonnet card. Assuming > it wasn't made up that would be pretty cool. > > I don't know how high a bus speed the Sonnet card could manage. The > max bus speed has more to do with printed circuit board design and > quality and little or nothing to do with which CPU is on board. Most > of the CPU card companies probably don't worry about optimizing the > design after they manage 50 MHz, because that is the nominal maximum > anyway. > > Tthe method behind this modification is to desolder the oscillator > (crystal?) and replace it with one with a higher speed. Most folks > aren't going to want to do that. > > However, I notice that the oscillator is a half-size metal can. I > know the small company Output Enablers used to sell a device called a > Chip Clip which would disable a full-size metal can oscillator and > replace its signal with a user installed oscillator. This might be > a nice application for their old product, assuming they ever made one > for half-size metal cans. Perhaps I'll email them about that... > > You can find the link to Output Enablers at "The Clock Chipping Home > Page" which is maintained by Marc Schrier. You should be able to > find a link to TCCHP in the links page at XLR8yourmac.com. > > Jeff Walther > > -- > SuperMacs is sponsored by <http://lowendmac.com/> and... > > Small Dog Electronics http://www.smalldog.com | Refurbished Drives | > Service & Replacement Parts [EMAIL PROTECTED] | & CDRWs on Sale! | > > Support Low End Mac <http://lowendmac.com/lists/support.html> > > SuperMacs list info: <http://lowendmac.com/supermacs/list.shtml> > --> AOL users, remove "mailto:"; > Send list messages to: <mailto:supermacs@;mail.maclaunch.com> > To unsubscribe, email: <mailto:supermacs-off@;mail.maclaunch.com> > For digest mode, email: <mailto:supermacs-digest@;mail.maclaunch.com> > Subscription questions: <mailto:listmom@;lemlists.com> > Archive: <http://www.mail-archive.com/supermacs%40mail.maclaunch.com/> > > --------------------------------------------------------------- > >The Think Different Store > http://www.ThinkDifferentStore.com > --------------------------------------------------------------- -- SuperMacs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | Service & Replacement Parts [EMAIL PROTECTED] | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> SuperMacs list info: <http://lowendmac.com/supermacs/list.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:supermacs@;mail.maclaunch.com> To unsubscribe, email: <mailto:supermacs-off@;mail.maclaunch.com> For digest mode, email: <mailto:supermacs-digest@;mail.maclaunch.com> Subscription questions: <mailto:listmom@;lemlists.com> Archive: <http://www.mail-archive.com/supermacs%40mail.maclaunch.com/> --------------------------------------------------------------- >The Think Different Store http://www.ThinkDifferentStore.com ---------------------------------------------------------------
