Reasonable Transfer Rates?

[Piyono]

I just purchased a Samsung SpinPoint SV1604N (5400 RPM, 160GB) to use as a backup drive for my photos. I also picked up an external USB 2.0 enclosure based on the ALi 5621 A1 chipset (inside of which, by the way, it was impossible to format the new drive - I had to hook it up to a different enclosure to format).

As I sit here and watch xxcopy fly my data to and fro I can't help but notice that the transfers are hovering around 8MB/s. Is that not awfully slow? I mean, sure, it's a slow drive and there's some system overhead and whatnot, but eight megs a second?

Out of curiousity I tried backing up the same source files to another external drive (Maxtor 250GB ML2P in a Bytecc enclosure with PL3507 chipset) and the rates weren't all that much better. Maybe in the order of 15MB/s.

Are these numbers normal or should I be investigating a problem?


]-[

 

[mubs]

15 MB/s sounds about right. Eight sucks big time. I have a WD 120GB 2MB 7200RPM external unit (whole thing made by WD) with FW400 and USB2 interfaces. In testing from my desktop I got:

a) 24.7 MB/s copying from desktop Ramdisk to external using FW

b) 21.7 MB copying from desktop HDD (WD 120 JB on a Promise Ultra 100) to external using FW

c) 18 MB/s copying from desktop HDD (WD 120 JB on a Promise Ultra 100) to external using USB2

The FW and USB2 controllers are made by Adaptec (2 separate PCI cards). Used Adaptec drivers for USB2 card; MS Windows native USB drivers were slower by 1 MB/s.

 

[time]

Sounds okay to me. You're transferring relatively small files so you won't get anywhere near the STR.

 

[Piyono]

So, given a single, 100MB file and 100 1MB files, the 100MB file will transfer faster, yes?
Why?

]-[

 

[Piyono]

I started getting copy errors so I pulled the drive out of the new enclosure and popped it onto a Bytecc BT-200. The difference was immediate and dramatic. Transfer rates roughly doubled and the copy errors were non-existent. Bytecc doesn't specify what chipset is used in the BT-200 and as I don't feel like cracking mine open I'll have to don my tweed cap and ask some questions.

In the meantime it would seem as though the ALi M5621 A1 and the controller on my motherboard don't care too much for one another.

Can't we all just get along?


]-[

 

[MaxBurn]

Because it's a sustained transfer, just reading and sending data instead of reading file information, looking for the file etc. The job files I work with have hundreds of 1 or 2k files in them, much faster to zip it up and shove it onto a USB device than to copy the folder with all the files in it directly.

I routinely burn DVD's from my USB laptop drives. Burner is 16x 22.160KB/s (well at the last part of the burn anyway).

I also just managed to copy 28gig from one of my older USB Laptop drives (has a toshiba MK4021GAS 4200RPM in it) in barely under 30 minutes.

 

[Piyono]

Ok, I cracked open my BT-200.
The bridge chipset is a Genesys Logic GL811E

However, I suspect Bytecc might use other chipsets in this device because the Windows98 driver package includes folders named
"AT2_CY68300 For Win98 Driver", "CS881x For Win98 Driver" and "M5621 For Win98 Driver", alluding to chipsets by Cypress, Myson Century and my new favorite, ALi.

Piyono

 

[CityK]

I had some difficulty with that Genesis chipset

 

[Piyono]

I had some difficulty with that Genesis chipset

Clearly the game of mating bridges to controllers is more involved than a spec sheet would have one believe.
I've spent the last couple of hours researching enclosures and it's becoming quite evident that no particular chipset is necessarily better or worse than any other. The key is finding a good match. With so many factors at play there's no telling, really, what will or won't work until the electrons start flowing.

When you find a combination that works well, stock up.


]-[

 

[LOST6200]

What transfer rates are obtainerd with AtTo?

 

[Piyono]

What transfer rates are obtainerd with AtTo?

I thought Atto made only Fibre Channel and SCSI stuff.

]-[

 

[Piyono]

What transfer rates are obtainerd with AtTo?

I thought Atto made only Fibre Channel and SCSI stuff.

Oh, wait... you mean the benchmark, don't you...

Yeah, haven't tried. Will test.

]-[

 

[Santilli]

ATTO shows about 13 mb/sec with my Maxtor 250 gig external.

USB 2.

Good enough for backups...

S

 

[Fushigi]

That WD external I mentioned in the Notebook Drives thread garners throughput around 25-26 MB/s respectively once the transfer size is 64 or larger.

Transfer size: 0.5-1024
Total length: 32mb
Direct I/O
Overlapped I/O
Queue depth: 4
ATTO is version 2.1