Firewire externals

[TheStu]

So, I have a MacBook, and a 500GB SATA USB external that I put together myself. I have been noticing lately that the transfer speeds have been much lower than they should be (4MB/s) and am now considering getting a firewire enclosure since I know that will be faster.

I know that Firewire can be daisy chained, and that is good because I also have 2 ATA notebook drives that I want to put into FW enclosures, and when I get around to upgrading the hard drive in my MacBook, I will want to put its old drive into a FW enclosure as well.

So, about the daisy chaining. Does anyone know if it would be best to put the most power hungry devices at the beginning of the chain, or the end? Also, would there be any benefit (when at home) to have the Wall Powered 3.5" external be the first in the chain and then all the bus powered 2.5" drives coming off of that, or does order not matter?

I am not concerned with transfer rates when it comes to chain location as much as I am power consumption. I don't want to starve the chain end devices because i should have put them in a different order.

Appreciate any answer you can give me

 

[Peter]

You should expect to get about 30 MB/s from USB 2.0 (a bit more or less depending on mainboard chipset), and you'll get around 40 MB/s from a perfect FireWire situation.

Daisy chaining bus powered devices is generally not a good idea. Use separate connectors on the host computer instead. But you are right in that it doesn't matter what self-powered device you plug the bus-powered ones into.

 

[TheStu]

Ok, 30MB/s? Really, I thought it was supposed to be around 12... I know that it isn't the 60MB/s that they proclaim since that is just burst, in perfect conditions, with the moon in alignment, and the computer gods smiling upon you.

Also, what is that 30MB/s contingent upon? I have a laptop, so we are dealing with a 5400RPM 2.5" drive as the source most of the time, writing to a 7200RPM Perp. Recording 3.5" drive.

See, the issue is that I only have 1 FW port on my system, and since I can daisy chain, I mean how bad is it? And when I was asking about the ordering issue, I was also wondering... lets say I have it like this

MacBook -> 3.5" Drive (AC Powered) -> 2.5" Drive (ata) -> 2.5" drive (ata) -> 2.5" drive (sata)

Would drives 2-4 maybe draw power through drive 1 in addition to the MacBook? Or would I be better off (in situation like that) having the AC adapters for the 2.5" drives as well?

 

[Peter]

Most 2.5" drives are marginal on the 500mA power allowance of USB anyway, so yes, running them AC powered is a much better idea anyway.

30 MB/s is what you can actually achieve with mass storage on USB 2.0 - if that particular mass storage is at least as fast, of course. Notebook drives may still be slower, but you'll be hard pressed to find a current 3.5" drive that is.

 

[TheStu]

Right, so there really is no reason why my external drive should be getting such slow transfer rates then?

 

[Peter]

Well obviously it did find a reason to perform this bad

It might be that the USB-IDE converter is running PIO instead of DMA. This happens when its firmware didn't detect and setup the drive properly. (It shouldn't happen with USB-to-SATA, but it is still possible to screw up like this even on SATA.) 4 MB/s would be about typical for this.

 

[fyleow]

..

 

[TheStu]

Originally posted by: Peter
Well obviously it did find a reason to perform this bad

It might be that the USB-IDE converter is running PIO instead of DMA. This happens when its firmware didn't detect and setup the drive properly. (It shouldn't happen with USB-to-SATA, but it is still possible to screw up like this even on SATA.) 4 MB/s would be about typical for this.

Any idea how to go about fixing the firmware? I am looking on the manufacturer's website, but it is weird to navigate. Looking inside the enclosure, it is using a jMicron chip, so should i go to that website?

Originally posted by: fyleow
If you're getting 6 MB/s through USB 2.0 then I don't think upgrading to Firewire is going to help. Like Peter said you should be getting around 30 MB/s. Have you tried transferring to the enclosure from your desktop?

Why would switching to FireWire not help? It would be the same drive sure, but it would be a new enclosure, and the firewire bus is completely different from the USB bus.

I have tried transferring to the enclosure from my MacBook in OS X and Vista. Both get about the same results. Also, get around the same speed in OS X, but on my friend's Core Duo MacBook Pro.

Testing the drive in same friend's Antec enclosure (looks identical to mine lol) yields something around 20-30MB/s (there is no speed indicator, so we went off of how big the file is/how long it took). So it looks like my enclosure is messed up... how unfortunate.

 

[fyleow]

..

 

[TheStu]

Originally posted by: fyleow

Why would switching to FireWire not help? It would be the same drive sure, but it would be a new enclosure, and the firewire bus is completely different from the USB bus.

Well the USB bus is more than capable of transferring at more than 6 MB/s so I don't think the problem is caused by it being USB.

So it looks like my enclosure is messed up... how unfortunate.

I'd look for a higher quality enclosure. I use an Azio enclosure and it looks and works well. Mine comes with eSATA and USB 2.0 but you can get it with just USB or USB + Firewire. Personally I'd stick with an enclosure that supports more than just Firewire for better compatibility with non Macs.

My point was that my understanding was that you were saying that it was my drive, but I just concluded that it wasn't. Mea Culpa.

Most every firewire enclosure that i have seen includes a USB port. But i will be getting a better one this time around.

 

[Peter]

In your position, I'd first try out whether your current USB drive assembly performs any better on someone else's system. If it does, then you've got a bottleneck inside your computer, and FireWire may just as well suffer it too.
And if it doesn't, then yes, it'll be time for a firmware upgrade first. These are best taken from the case manufacturer, since the chip maker's generic firmware may not work with the particular use of the chip.

 

[Soundmanred]

I have two Seagate externals with both USB 2.0 and Firewire, and the transfer speeds are about the same with either connection option.