USB 2.0 external drive ?? help

[adid1]

I've just installed a Seagate 80 GB disk in a MAP-H31U2 case.
Its a USB 2.0 unit, I'm using XP SP2 with 2GB Pentium 4
with USB 2.0 support.

I did a simple 700 MB file transfer to the external drive
it took about 55 sec.
I don't think its fast enough.

Is there anything else I need to check,
What is your experience with USB 2.0 external drives ?

 

[Tod]

I've just installed a Seagate 80 GB disk in a MAP-H31U2 case.
Its a USB 2.0 unit, I'm using XP SP2 with 2GB Pentium 4
with USB 2.0 support.

I did a simple 700 MB file transfer to the external drive
it took about 55 sec.
I don't think its fast enough.

Is there anything else I need to check,
What is your experience with USB 2.0 external drives ?

USB 2 will not transfer as fast as ATA-100/133
To me your 11MB per second transfer is reasonable.

 

[J. Clarke]

USB 2 will not transfer as fast as ATA-100/133
To me your 11MB per second transfer is reasonable.

While it is "reasonable" it's not for the reason you state. USB2 will if
everything is set up perfectly transfer 60 MB/sec. Usually the slow
transfer comes about due to the USB-to-IDE bridge chip used in the external
case. A different case might give better results.

 

[Eric Gisin]

What bridge chip delivers 480Mb/s? Hard to believe there is no overhead in USB
2.

 

[Frank W.]

While it is "reasonable" it's not for the reason you state. USB2 will if

everything is set up perfectly transfer 60 MB/sec. Usually the slow
transfer comes about due to the USB-to-IDE bridge chip used in the external
case. A different case might give better results.

Any websites that you recommend on this? It would be a shame to suffer for months with slow transfer
rates just because of a chip that could be replaced.

 

[J. Clarke]

Any websites that you recommend on this? It would be a shame to suffer
for months with slow transfer rates just because of a chip that could be
replaced.

I don't know of any sites that do a good comparison of different USB-to-IDE
bridge chips. Dansdata <http://www.dansdata.com/combodock.htm> tested an
Oxford OXUF922-based device and gets about 72% of the drive's native
performance out of it under USB2, which sounds like considerably better
than you're getting out of whatever bridge you're using. I don't know of
any that do better than that.

This was a real problem for Firewire for a long time as well--Oxford was the
first bridge chip that got really good performance out of Firewire-attached
IDE drives.

 

[Odie Ferrous]

While it is "reasonable" it's not for the reason you state. USB2 will if
everything is set up perfectly transfer 60 MB/sec.

I find this quite amazing.

In one of my machines I am running a RAID 0 array with 2 x 10K rpm U160
drives and I don't achieve 60MB / sec transfer. (Benchmark tests show
up to 650MB (six hundred and fifty megabytes) per second, but that is
through the cache memory and not "real life". Not when physically
copying files...)

Would that I could have 60 megabytes per second with USB or Firewire.


Odie

 

[J. Clarke]

I find this quite amazing.

In one of my machines I am running a RAID 0 array with 2 x 10K rpm U160
drives and I don't achieve 60MB / sec transfer. (Benchmark tests show
up to 650MB (six hundred and fifty megabytes) per second, but that is
through the cache memory and not "real life". Not when physically
copying files...)

Would that I could have 60 megabytes per second with USB or Firewire.

You're confusing system throughput with interface throughput. USB2 can
deliver 60 MB/sec. That does not mean that any particular disk that can be
attached to a USB2 bridge can deliver 60 MB/sec to that bridge.

My point is that USB2 is, in the case described in which the achieved
throughput was 12MB/sec, not the bottleneck. The disk might be or the
bridge might be, but USB2 itself is not.

 

[Folkert Rienstra]

While it is "reasonable" it's not for the reason you state.

But you will correct that now, yes? ROTFLOL.

USB2 will if everything is set up perfectly transfer 60 MB/sec.

Nonsense. Absolutely impossible.

 

[adi doron]

Well guys,
I opened the case again and looked on the USB chip,
Its GL811E, I'm reviewing the pdf I found on the net.
I guess its a crap if it gives only about 12 MB/s