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John123 · Jun 1, 2006, 12:10 AM

I've been using SuperDuper to back up my MBP's contents. When I first started using it, it would back my drive in about an hour. I loved it.

These days, somehow, my throughput has dropped WAY down -- to around 3-4 MB/s, so it takes around 6-7 hours to finish. My volume of data and my type of data have really not changed over time. I've tried this over FireWire and USB 2.0 with the same results. For reference, my main external drive is in a MacAlly FW/USB enclosure, although I've tried another USB 2.0 enclosure with a SATA drive, and I get similar results.

I am wondering if this has happened to anyone else, and if so, whether anyone has any insights. It is very frustrating, and I would like to figure out what is going on.

Simon · Jun 1, 2006, 04:07 AM

My MBP transfers data from its internal SATA disk to an external PATA disk (LaCie, 7200 RPM/8MB, 160GB) over FW400 at roughly 30MB/s. I've never had the problem you're describing.

John123 · Jun 1, 2006, 09:47 AM

Hmmm, bummer.

lilrabbit129 · Jun 1, 2006, 10:25 PM

I had something similar on my 12"PB over FW. It was fixed by running a defrag on the external HD. It seems that fragmentation, when it happens on an HFS+ drive degrades performance severely.

uicandrew · 09:11 AM

i used superduper on my intel imac and get roughly 3.8-5 MB/s to a usb 2.0 2.5" external enclosure. it starts off pretty slowly and then it gets faster.

also, in the pc world, i think moving a much of small files (ie - my music collection) takes longer than moving the same amount of info, but in much larger files (ie - my videos) so i'm not sure if this has anything to do with this.

i recently bought a firewire/usb 2.0 combo 2.5" external enclosure. i'll report back how well it does.

Simon · Jun 2, 2006, 03:52 AM

Originally Posted by uicandrew

i used superduper on my intel imac and get roughly 3.8-5mbps to a usb 2.0 2.5" external enclosure.

Are you sure about that? Do you really mean Mbps or MB/s? If it's the former it totally sucks. If it's the latter it's still pretty bad.

I'm observing ~30MB/s and John123 is getting 3-4MB/s. Something's fishy if you're getting those low speeds.

uicandrew · Jun 2, 2006, 09:23 AM

Originally Posted by Simon

Are you sure about that? Do you really mean Mbps or MB/s? If it's the former it totally sucks. If it's the latter it's still pretty bad.

I'm observing ~30MB/s and John123 is getting 3-4MB/s. Something's fishy if you're getting those low speeds.

yeah, thanks for the correction, i meant MB/s. i think i transfered 30gb or so in 1.5 hours. but then again, barefeats.com reports that usb transfer is faster with intel mac than PPC mac.

actually, i think barefeats.com has the explanation of the OP's problem

http://www.barefeats.com/hard69.html

(trust me, it is a legit link. barefeats is a hidden gem of benchmarks, not a porn site)

Simon · Jun 2, 2006, 09:34 AM

Even if the BareFeats tests are right, John123's speeds are still far lower. Something's wrong there, but I really don't know what's going on.

Big Mac · Jun 2, 2006, 09:35 AM

Yeah, it should be going far faster than that.

Simon · Jun 2, 2006, 09:44 AM

And btw, it's not just a USB/Mac problem, since John123's already mentioned he saw no improvement when using the FW port. I'm guessing there is some problem with the bridge chipset in the external disk. John123, have you made sure that the external HDD's firmware is updated?

John123 · Jun 2, 2006, 07:44 PM

Well, here's an update. On a hunch, I restarted the computer in safe mode. And voila -- transfer speeds were back to where I expected. This told me it wasn't a hardware/chipset problem.

So, I reinstalled the OS (and to be safe, didn't restore any settings), and I'm going well again.

This strikes me as very weird. What kind of software could consistently limit the throughput of both USB and FireWire ports? I'd done all the usual troubleshooting steps (repairing permissions, checking my RAM), so I am perplexed. I'd be interested to hear others' reactions on this one.

Simon · Jun 3, 2006, 01:45 AM

Very interesting.

Do you have any apps that install kexts or apps that use special drivers for USB or FW?

certmagic · Jun 3, 2006, 10:40 AM

I'm using superduper to backup onto a portable HDD (Seagate 100gb 5400RPM n a Nexstar 3 enclosure) through FW400 and I get between 10 - 13.6MB/s. So is this considered fast or slow?

Also, could the quality of a cable affect the speed? On my cables included with my Portable HDD I get 10MB/s but with the one given by M-Audio, I get 13.6MB/s

John123 · Jun 3, 2006, 02:22 PM

Nope, not a damn thing that should fiddle with USB or FW drivers. I'm pretty minimalist. In fact, since I did a reinstall of my OS about a month ago, there is actually a bunch of stuff that I usually would install but haven't. I'm out of ideas....weird, though.