>Since a firewire hard drive is just an IDE hard drive with an added >chipset, is it any faster or better than just using an IDE hard drive?
It has the plug and play/portability/convenience advantages, but it is definitely not faster than plugging straight into an available IDE chain. There's some amount of overhead involved in switching IEEE1394 and Parallel ATA and with your machine in converting IEEE1394 into something the computer can understand. If your 1394 card is plugged into your PCI bus, there's a bottleneck there too as the 1394 interface competes with whatever else you have on your PCI bus for bandwidth. Of course, in the S900 your IDE controller is on the PCI bus as well, so that penalty would apply anyway. >With nothing technical to back it up, I would venture to say the throughput >speed of Firewire 400 does not take advantage of the 7200 RPM IDE drives >that are typically used in Firewire drives. That's not entirely true. I know of no drives that come anywhere near the maximum theoretical speed of the protocol they use. The best 7200RPM drive I have used has a real speed in my PC of around 54MB/sec (Western Digital Special Edition 160GB w/ 8MB cache), while IEEE1394 has a maximum theoretical speed of 400MB/sec for Firewire 400 and 800MB/sec for Firewire 800. Most of today's parallel ATA hard drives conform to either the ATA100 or ATA133 specification, the maximum theoretical bus speed listed in their names (100MB/sec and 133MB/sec respectively). The nice thing about the ATA specification is that it's backwards-compatible, so ATA133 drives are capable of operating at ATA100, ATA66, ATA33, DMA, and PIO. General rule of thumb: the more times you change buses, the slower the device will run. Unfortunately for us, manufacturers do not publish the real speeds of their drives, instead referring to the maximum theoretical speed of the protocol they support. This is why I view ATA133 as such a joke; we're only now just beginning to saturate the ATA66 protocol. I can sympathize somewhat with the drive manufacturers on this one, since the real speed of their drives depends on the system the drive is attached to just as much as the drive itself. For instance, since any IDE controller you add to your S900 will be on the PCI bus, your drive speed is going to be less than if the drive were plugged into a modern PC with the IDE controller integrated into the motherboard core logic. Having a fast processor helps too. >Each bridge is based on one of a limited number of chips, and there >are opinions (with which I am not familiar) about the quality and >performance of the various available chips. So the bridge matters as >well as the model of drive. I did some homework on this a little while back, and apparently the Oxford 911 is the best FW400 bridge chipset in terms of having the lowest performance penalties (BareFeats was the source I think). It should be noted that it will operate your hard drive in ATA66 mode, which is true for all of the chipsets I looked at. If you have FW800 ports, you might be able to find a external drive with the Oxford 922 chipset, which is fast but suffered some driver problems with early releases of Panther. I don't know whether or not this issue is resolved yet, but I see it as fairly pointless since there's no way the drive can saturate that bus unless you daisy chain 10 of them. My personal recommendation is to buy a drive that suits your needs, then to get an empty enclosure that suits your needs, and then assemble your own portable drive. Depending on where you purchase your parts, the end product may come out to be cheaper than getting a pre-assembled unit. -Drew B -- SuperMacs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | Service & Replacement Parts [EMAIL PROTECTED] | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> SuperMacs list info: <http://lowendmac.com/supermacs/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/supermacs%40mail.maclaunch.com/> --------------------------------------------------------------- >The Think Different Store http://www.ThinkDifferentStore.com ---------------------------------------------------------------
