On Aug 4, 2010, at 5:37 PM, Mark Sokolovsky wrote: > Hello, everybody.... I have an external 2.5" drive sitting inside my PM G4 > plugged in through USB 2.0 (A PCI card) and normally, whenever I transfer > things between the Main system HDD and the external 320GB HDD, the transfer > speed is literally 500Kb/s. For some reason, yesterday, when I restarted, the > External HDD hot-wired itself, and sped up the file transfer speed to 690MB/s > for some strange reason. This only works between the main HDD and the > external drive. One day I was copying a 100MB Mac OS 8 ISO from the main HDD > to the External HDD and it took about 27 minutes. The next day, I restarted, > and I copied the ISO of Kubuntu 10.04 from the network to the system's main > HDD, and that took about 3 hours. I then copied the ISO from the HDD to the > External drive, and it literally took 1.2 seconds. I verified the image and > i'm not lying, something in there is hotwired. I was able to copy a DMG image > of Leopard (Which BTW is 7.8GB in size!) for the use of my Virtual Q emulator > system in about 8 seconds. > > So tell me wise users of Lemlist.... I didn't do anything to hotwire the > machine to do this, and I was able to copy a 7.8GB file in 8 seconds... how > is this possible through USB 2.0?
It isn't possible. USB 2.0 has a maximum transfer speed of 480mbps which translates into roughly 50MB/s maximum theoretical speed. In actual practice the speed cap is around 35-40MB/s. In addition, the maximum bandwidth of the PCI bus is 133MB/s between ALL slots in the system, this means that your transfer speed from your main internal hard disk is part of this speed. Even over a gigabit connection or between 2 SATA II hard drives, you can't copy a 7.8 GB file in 8 seconds. Methinks you made an alias instead of actually copying the file in question. It isn't possible to copy a file that large in that short of a period of time through ANY interface in your computer. In an Intel Mac with superfast RAID arrays or something, perhaps, but not a G4 of any shape, form, or fashion. -- 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
