> From: "Mark Tribble" <[EMAIL PROTECTED]> > > Date: Sat, 14 Dec 2002 22:14:49 -0600 > > > I have a few questions about this. What kind of IDE bus does the C500 > have (e.g., 33.3 MB/s Mode 2 Ultra DMA, 16.6 MB/s Mode 4 PIO, 16.6 > MB/s Mode 2 multi-word DMA, etc.)? What is the difference between an > internal bus and an external bus? The C500 has an external DB-25 SCSI > connector and an internal 50-pin SCSI connector. The CD-ROM drive is > connected to the 50-pin SCSI connector with a ribbon cable. What do > you mean by "switching that bus for internal use"? All I did was > replace the ribbon cable (which only had one connector) with a ribbon > cable that had two connectors so I could hook up both the SCSI hard > drive and the CD-ROM drive. I think I disabled the terminator on the > CD-ROM drive and activated the terminator on the hard drive.
The IDE bus in the C500/600 is 16.6MB sec likely Mode 2. I'm guessing Howie is mixing the C500 up with the S900/J700 ;-) which does have 2 SCSI buses. The C500/600 while it does have an internal SCSI plug for the CD ROM has only one slow 5mb sec SCSI bus. > Hard drives can never actually match the theoretical transfer rates of > the interface they're attached to. The IBM SCSI hard drive I'm using > can achieve a sustained transfer rate of 3.8-5.7 MB/sec. The burst > transfer rate could not exceed 10 MB/sec (the interface limit). I'm > sure the drive could saturate the 5 MB/sec SCSI bus, but I wonder how > badly the performance would actually suffer from it. > > Just for the fun of it, I'd like to run some benchmarks to compare the > performance of the Western Digital UDMA/33 drive and the IBM > Fast-SCSI2 drive in a C500. Even on a 5 MB/sec SCSI bus, the IBM drive > has some advantages over the Western Digital (seek time, latency, > cache size, etc.) and I wonder how much difference theoretical > transfer rates make in the real world. Can you recommend some > benchmarking software? While you are correct about theoretical hard drive rates never being met in real world use. A modern IDE drive will run circles around a SCSI drive even in the C500 ! I know I tested mine and was surprised how much faster in real world use the IDE drive was. As for a hard disk driver, I always suggest sticking with Apple > drivers. Although Apple Drive Setup doesn't recognize all drives, > and you may need to use a different utility. If so, I think it's > best to avoid older versions of FWB hard disk toolkit. Too many > trouble reports with the old versions. Great advice . I recommend not using FWB if at all possible. If you have to speed money because Apple drive setup won't work with your drive your better off buying a new drive then buying or paying to upgrade FWB. Ok to use if you already have it but sooner or later it will no longer work without speeding more money when upgrading your OS. > I've been able to boot from the original IDE hard drive, a floppy, an > Apple 2x CD-ROM drive, and a 230MB SCSI hard drive. I haven't been > able to boot from the IBM SCSI hard drive (which was initialized on > another machine) or the Toshiba 12X CD-ROM drive or a CyberDrive 24X > CD-ROM drive. I tried to use the Apple CD-ROM 5.4 driver, but it > didn't help. I'm still not sure which drivers I need, or whether I > need to re-initialize the IBM SCSI hard drive. You need the universal Apple CD ROM driver 5.3.1 and 5.3.2 for audio disks available @ http://www.macdrivermuseum.com/disk.html Intech CD speedtools are great drivers but not free. > Thanks for your help! > > Mark Had to add my 2 cents hope this helps Will S -- 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 ---------------------------------------------------------------
