> A 7,200 RPM HD is DEFINITELY faster in a FW400 enclosure than either a > 5,400 RPM or 4,200 RPM. Have you ever even booted from Firewire on a > daily basis? Have you made measurements? Have you streamed video off a > Firewire enclosure? Obviously your experience is limited.
The rotational speed of a drive (3,600 rpm, 4,200 rpm, 5,400 rpm, 7,200 rpm or, indeed, infinite rpm) directly impacts the "latency" of a drive's performance, generally taken to be one-half of the reciprocal of the effective rpm of the drive. Indeed, using this measure alone, a 7,200 rpm drive is "twice as fast" as a 3,600 rpm drive. Yeah, right! (3,600 rpm WAS the classic speed of a mainframe drive, but as the demand for higher-capacity drives became evident, the only way to achieve the required higher capacity, within the same hard drive FORM FACTOR, was to REDUCE the rpm, thereby giving a 9 GB capacity from an otherwise 3 GB capacity drive, or an 18 GB capacity from an oherwise 6 GB capacity drive, etcetera). Yet, the average throughput capacity of most drive electronics and host bus adapter electronics remained essentially the same, at about 40 megabytes/second, MAXIMUM. And, the average latency is still one-half of the reciprocal of the rotational speed. Can't change physics. It is immutable. -- You received this message because you are a member of G-Group, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to g3-5-list@googlegroups.com For more options, visit this group at http://groups.google.com/group/g3-5-list
