SATA 3 Transfer Slow

[AA5B]

Please excuse my simple question, but I would appreciate some insight / direction.

Why does it take soooooo long to transfer files from a RAID stripe set to an eSATA connected SATA 3 drive?

System:
-Dell Workstation 690
-Stripe Set using Dell motherboard RAID controller - using 2 WD 7200rpm Drives
-eSATA connection to BlacX eSATA dock with 7200 rpm WD SATA 3 drive
-Win XP
-4GB RAM / 2-Dual Core 3.0 GHz Zeon processors

It's taken about 80 minutes to transfer 150GByte file (1.88 GB / min)...

With SATA 3 speeds being 3.0 G / Sec and the RAID set having even higher performance, I just don't see how it can take so long for such a transfer take place.... evening allowing for overhead of Win XP, etc...

Let's say the machine could only get 0.5 G / Sec transfer instead of 3.0 G, it should only be around 6 mins -- not 80.

Also -- I did go to Computer Admin > Device Manager > IDE ATA/ATAPI Controllers > Primary IDE Channel -- and made sure Ultra DMA 2 is selected. (There are two other controllers listed: 1) Intel 631xESB/6321ESB Ultra ATA Storage Controller - 269E, 2) Intel 631xESB/632xEST SATA AHCI Controller..... However, neither of these controllers have an "advanced" tab to confirm the Ultra DMA is being used.)

Any insight is welcomed.

 

[sminlal]

The data rate you're quoting is around 30MB/sec, which is what one normally sees when using a USB 2.0 connection. Have you connected the drive via an eSATA cable or a USB cable?

 

[AA5B]

The data rate you're quoting is around 30MB/sec, which is what one normally sees when using a USB 2.0 connection. Have you connected the drive via an eSATA cable or a USB cable?

It is connected via eSATA, not USB.

 

[sminlal]

OK, I had to ask. A lot of external drives can be connected either way, and if you had used the USB connection then it would have fit the data rate perfectly.

Is the CPU 100% busy (or close to it) while doing the transfer, even though no other programs are running? If so, then it's probably a DMA issue.

Are either the source or target drives of the copy doing anything else? Any other file access at the same time as the copy will slow things down significantly.

 

[sub mesa]

BTW:

"Also -- I did go to Computer Admin > Device Manager > IDE ATA/ATAPI Controllers > Primary IDE Channel -- and made sure Ultra DMA 2 is selected."

The fact that you select to use DMA mode means nothing. You need to actually see the CURRENT mode in use; and it can be PIO mode even though you selected to use DMA mode.

A simple HDTune benchmark will show immediately whether you have a PIO problem.

 

[AA5B]

Best answer selected by AA5B.