bus speed vrs. drive spped

[372cat]

Given the 133 mhz bus in my G4 500, would an ATA100 offer any benefits over an ATA66? I have my strengths, but as you can see, they don't run to the technical!
Thanks

[M.Brane]

Probably, but it depends on the rating/quality of the drive/drivers.

[Sugarite]

Current hard drives can't saturate an ATA66 bus, and ATA100 doesn't improve access times, so you're better off just getting the best hard drives (I like IBM Deskstars). No hard drive interface is going to come close to saturating your system bus. You might consider a SCSI hard drive setup, ATA uses CPU cycles, so you should be able to use more plugs with a SCSI drive, though the cost makes it a judgement call.

[Targon]

The new Mac's only have a ATA/66 bus. This means that the ATA/100 drive you put on the buss will only have the thruput of the bus it is on.

Just buy an IBM Deskstar 60GPX series ATA/100 drive. ATA/66 drives are getting scaled down in production anyway, also chances are your next Mac will have an ATA/100 interface....that is of course if the ATA drives lasts that long [img]images/icons/wink.gif[/img]

If any bus was to be saturated it would be the PCI bus and fast Segate Cheetah drives on Dual channel Ultra3 ATTO controllers could easily do this.

Targon

[Sugarite]

33mhz x 64-bit ÷ 8 bits/byte = 264MB/s of throughput on PCI bus. While dual U160 SCSI could see bursts of 320MB/s, you're not going to see that kind of burst from current drives. Besides, 24 tracks of audio only needs 3.6MB/s or so. U2W SCSI is plenty of overkill.

[KamaSutra77]

Unfortunately it is not only Hard drives which work off of the bus, or with it. Video also uses a fair amount of bandwidth, hence the stuttering clearly evident when multiple monitors are used on some systems, which otherwise perform well. So figuring bandwidth and throughput capacities relative solely to average/burst rates for SCSI/PCI/ATA drives is not sufficient. Cheers.
The bus speed is 100 on most new macs. Old G3's still used 66, like most powerbooks, except for the Ti G4.