At 12:54 -0500 04/02/2002, John Albert wrote:
>(NOTE: my s900 *is* "PCI standard 2.1 compliant" >-- it worked with the original TurboMax card without stuttering, and does the >same with the newer VST "Ultratek" card I'm using in it now.) Actually, the PCI compliance that Apple aimed for with the generation of machines that included the S900 was PCI 2.0 and they missed even that target. Interestingly, the Apple Network Server which uses the same chip set is supposedly 2.1 compliant, so it must have to do with a difference in the ROM code. Umax support blew a lot of smoke about PCI 2.1 compliance and the lower slots and we all bought it because who knew better? But that's all it was, is smoke. They may have believed it themselves, but the fact remains that there are severe bugs in the PCI implementation. Fortunately, they don't rear their heads until you're using more than one level of PCI Bridges, but PCI Bridges are an official part of the PCI specification and Apple should have implemented support for them properly. By putting a PCI Bridge in the S900, Umax insured that we would meet this bug any time we added another device with a PCI Bridge. >I will note that the card *I* used was the original ProMax "TurboMax" >ATA/33 card. The two more recent cards I mentioned have "fixes" to alleviate >the audio stuttering, but I have no direct experience as to whether they would >(or would not) experience the same problems in a c600 clone, or whether the >"stuttering fixes" released for these cards would be effective. The TurboMax ATA/33 card has terrible (i.e. only accidental) ATAPI support according to most of the reports on Mike's XLR8yourmac.com site, unless I'm misremembering. But the C600 is based on the 6400/6500 architecture which has a known bug with PCI Bridges and so it may not work so well with IDE cards, because the dual channel nature of the cards seems to invoke the bridge bug in some cases. I would enjoy reading the results of your testing if you were to repeat it with the Sonnet Tempo card. It is supposed to have better ATAPI support than the TurboMax and does not appear to have the "bridge resemblance" that the VST card has which sets off these Apple bugs. 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! | SPECIAL SM LIST PRICES - 24x Bootable SCSI CDROM $39.99, Umax Processors $19.99 PowerSupplies from C500/C600 $49.99 J700/S900 $79.99 <mailto:[EMAIL PROTECTED]> Support Low End Mac <http://lowendmac.com/lists/support.html> SuperMacs list info: <http://lowendmac.com/supermacs/list.shtml> 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/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
