on 9/15/03 11:33 AM, Jeff Walther at [EMAIL PROTECTED] wrote: > At 22:24 -0400 09/14/2003, Ken Hjulstrom wrote: > >> Last fall, I tried to set up my J700 in a similar manner with a Sonnet 800Mhz >> G4 card. I got as close as you did, too. OS X would sometimes run, >> sometimes >> for about an hour, but eventually the system would completely lock up and >> nothing short of powering the system down and back up would help. And since >> the crash was unexpected, it seemed to leave some of the apps in a bad >> state, >> often resulting in apps that would never start up again unless I >> reinstalled OS X. >> After over a month of tweaking XPostFacto, swapping memory modules in and >> out, I finally called Sonnet and asked the tech support person point-blank >> if >> there was a known problem with their Crescendo 800 Mhz G4 card and the >> J700. > >> The tech person told me that they were having lots of reported problems with >> this, and he said that one of the problems may be due to the fact that the >> Crescendo 800 Mhz card requires that memory NOT be interleaved. > >> I still find it odd that this accelerator card, which works fine >> under 9.1 would not >> work under OS X. This is the first piece of hardware I've encountered which >> became incompatable wtih installed memory due to an OS upgrade.
OS X will not run with poor ram that will run fine with OS 9. I have seen this documented on lots of discusion boards and have had the same problem with my 8600/G3/375 when I had anything other than 128mb chips installed. > The reason you find it odd, is because you are a perceptive person > and Sonnet tech support doesn't have a clue. It's exceedingly > unlikely that interleaving is the problem and if it were, all of the > machines for which the G4/700 & 800 were built would be having the > same problem whenever memory was interleaved. Such a symptom would > reduce the memory capacity of these machines by 25% and slow memory > access by 10 - 15%. Both from my experience and from what my local Mac tech guys have said I agree that interleaved memory will cause problems with G3 / G4 upgrades as well leaving in the cache card. The cach card will stop some from booting all together. I haven't seen all the mac logic boards but it seems to me that the only ones that have soldered cahe were performas. The top end 8600/250+ and 9600/250+ being the exceptions as they have the cach on the processor card. > However, it's a conveniently difficult to check this claim by Sonnet. > Much more likely is that all the extra logic they loaded onto the > card to handle the six slot machines (9500, 9600, not S900) and make > the caches work properly are causing some low level problem with > OSX's kernel and they probably didn't test with X during development. > > Changing their "magic voodoo logic" now would mean changing hardware > and that's expensive, so they'll just continue to sell the card the > way it is, in it's broken state. > > Your suggestion of disabling the S900's onboard cache is a good idea > for a test. If the root of the problem is the logic that makes the > 7455's cache levels work properly, then the onboard cache could be > interfereing. However, if this were the problem, then the 9500 and > original 9600 should have the same problem, because their caches are > soldered down too and they don't have a convenient jumper for > disabling the cache. You have to remove resistor R31 on those two > machines. > > 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:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/supermacs%40mail.maclaunch.com/> --------------------------------------------------------------- >The Think Different Store http://www.ThinkDifferentStore.com ---------------------------------------------------------------
