thread was Re: Mac Mini "Tom" <[EMAIL PROTECTED]> wrote: >> You are correct, but to be clear. 400 M/bit per sec, not 400 M/Bytes >> per second. Big B is Bytes, little b is bits. >> >> USB2.0 is 480Mb/sec, which is still slower than FW due to excessive >> overhead. To which Kyle Hansen <[EMAIL PROTECTED]> >FW400 (400Mbps) and USB 2.0 (480Mbps) are the same in real world >speed/throughput tests. And what do you mean when you say "excessive >overhead?" I have never heard that term in the computing world. > >FW800 is where it's at. No doubt Kyle, but . . .
IIRC Apple's FireWire data transfer protocols are closely related to (derived from?) SCSI. SCSI (and FireWire) adapters use much less of a host system's other resources than does USB. IIRC (and I'm sure y'all will correct me if I'm wrong) USB requires the host to spend significant other resources managing data flow, hence (I think) Tom's reference to "excessive overhead". While I haven't any specifics to quote, IIRC (again the IIRC! :) USB 2.0 doesn't come close to even FW400, especially when more than a couple of devices share the same bus. USB's underlying data transfer protocols aren't nearly as robust as are those of FireWire. I think FW vs. USB2 is like comparing SCSI vs. ATA. ATA drives may perform acceptably for single users/simple jobs, but when the tasks begin to multiply, nominally similarly specced SCSI subsystems generally handle complexity much better than their ATA counterparts. from <http://www.usb-ware.com/firewire-vs-usb.htm> [quote] FireWire vs. USB 2.0 - Architecture *FireWire, uses a "Peer-to-Peer" architecture in which the peripherals are intelligent and can negotiate bus conflicts to determine which device can best control a data transfer *Hi-Speed USB 2.0 uses a "Master-Slave" architecture in which the computer handles all arbitration functions and dictates data flow to, from and between the attached peripherals (adding additional system overhead and resulting in slower data flow control) [/quote] Seriously, are there any big-data users out there who prefer USB 2.0 over FireWire400 for big data transfers? If one's livelyhood depends on pushing around many large files quickly and reliably, who ya gonna call? Well, nowadays, you probably won't choose either, there are even faster data busses like fibre channel . . . but between these two, which? A quick google [firewire versus usb] found some more relevant pages: <http://www.mackido.com/Hardware/USB2.html> <http://www.pcstats.com/articleview.cfm?articleid=1104> Sorry for all the IIRCs, I don't have enough details and references at hand and must rely partially on leaky brain cells from which to (slowly) recall data. :-\ <G> Hmmm, brain cell data transfer speed = . . . ADB? Serial? <G> dan k ................................. http://macdan.n3.net/ carracho://dankephoto.dhs.org:9700 hotline://dankephoto.dhs.org:9500 ................................. -- G-List is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | -- We have Apple Refurbished Monitors in stock! | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> G-List list info: <http://lowendmac.com/lists/g-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/g-list%40mail.maclaunch.com/> iPod Accessories for Less at 1-800-iPOD.COM Fast Delivery, Low Price, Good Deal www.1800ipod.com
