[EMAIL PROTECTED] writes: > >The 50 MHz, maximum, bus of the older machines, including the 9600, limits >the aggregate throughput of the machine. > >Beige machines have a 66 MHz bus, but are also somewhat limited. > >B&W and later machines have higher speed buses. > >In any case, the cards are buffered, as are the drives, so you really can't >overrun or underrun the cards or the drives. > >The bottom line, as always, is the overall system will perform only as fast >as the slowest component, which may in fact be the system bus.
I would be very surprised if the system bus proved to be the bottleneck for any single-disk throughput. The standard 32-bit 33 MHz PCI bus has a maximum bandwidth of 133 MB/s. Of course, you'll never see all that bandwidth in the real world but it's more than enough to drive any IDE disk at sustainable speeds. You might lose a bit off the peak rates (basically filling or emptying the cache on the disk), but that's it. For a single current-model IDE disk, you're looking at a sustained transfer rate of between 30-40 MB/s. With a raid setup, you might get close to doubling that. So, in almost all cases, the disk will be the bottleneck. So, for any single disk application, ATA66 should be adequate. For a raid configuration, you might want to go to ATA100 or ATA133. As previously mentioned, support for large (>120GB) disks is another important factor and may only be available on the faster cards. Hope this helps, -Jeff [EMAIL PROTECTED] -- "You can't brew a premium lager with a kool-aid mentality." --Harold Green in _The_Red_Green_Show_ -- PCI-PowerMacs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | -- Sonnet & PowerLogix Upgrades - start at $169 | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> PCI-PowerMacs list info: <http://lowendmac.com/lists/pci-powermacs.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/pci-powermacs%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
