DriveStation combo 4 eSATA connection not working

[percoplus]

   

I have an eSATA adapter cable from the Buffalo drive directly to the SATA port on the Motherboard. Drive does not show up. I have no external SATA port nor FW 800.

 

USB2 and Firewire 400 works but transfer very slow. FW 400 about 40 M/sec. USB2 starts out at 100 M/sec but then slows down to about 25-30 M/sec. Moving video files (1 GB and 7 GB) from the Buffalo to/from the C drive. Slow even with Turbo USB activated.

 

Generic USB driver is Microsoft version 6.0.6001.18000 dated 6/21/2006. I don't know if there's an updated driver, but it is plug-n-play.

 

I am running Vista 64 Ultimate, 8 GB RAM. Ishould see better performance.

[Colin137]

Some internal SATA controllers do not support the voltage requirements of eSATA; thus the included adapter will not necessarily work in some systems.

 

40 MB/s is 320 Mbit/s, which is a reasonable percentage of the 400 Mbit/s limit on Firewire 400, and fairly typical for firewire drives.

 

25-30 MB/s is also fairly typical for USB.

[percoplus]

   

Okay, thanks for the MB to Mb conversion info. FW 400 and USB is not doing the job for me. It would be okay for backups, but not editing.

 

I now have the Buff drive attached to a 3rd party eSATA card. Large files move from the Buff drive to the desktop at 80 MB/sec, but going other way transfer is 400 MB/sec. Is that normal? What could cause the speed difference?

 

All my drivers and BIOS is up-to-date as far as I can tell.

 

Before the 3rd party card, I had an adapter cable from the Buff direct to a free SATA port on the motherboard. No mount. I have tested those ports with internal drives okay. The computer manufacturer HP advised me to connect that way as an option. I would expect they would know about compatibility and power issues. Maybe I should call them back.

 

Thanks for the help.

 

Alex

 

 

[Colin137]

Let me confirm that over eSATA you're getting 80MB/s READ speeds and 400MB/s WRITE speeds? I suspect you switched the numbers or added a zero, because normally READ speeds are much higher then WRITE speeds, and 400MB/s isn't only impossible for a 7200 RPM disk, it's impossible for SATA as well... 400MB/s corresponds to 3.2 Gbit/s... SATA's limit is 3.0 Gbit/s.

 

SATA and eSATA use the same signalling protocols, but the voltage requirements are different. For eSATA:

• Minimum transmit potential increased: Range is 500–600 mV instead of 400–600 mV.
• Minimum receive potential decreased: Range is 240–600 mV instead of 325–600 mV.

 

[percoplus]

   

It's exactly as I said, but I'm just looking at the speed given by Windows Explorer as the file is being moved. Doesn't look reliable at all as numbers fluctuated. I just moved a larger file about 5 GB to/from Buffalo. Both directions 100 MB/sec did not fluctuate this time.

 

I tested another ext drive WD MyBook with eSATA. Transfer speed was the same in both directions. Moving a 1.5 GB file started out at 500 MB/ sec but then slowed down to 100 MB/sec - both directions.

 

I don't know what to make of this. For all I know it could be normal. My editing program is a little sluggish, but this is a fast machine. Do you know of a better way to test transfer speeds? Vista Ultimate 64 doesn't seem to have any utilities. Is there something I can download?

 

I have 2 SATA drives RAID setup as the system drive. Buffalo drive ext eSATA and MyBook eSATA.

[Colin137]

I don't personally know of any utilities for testing transfer rates, but if you time the transfer, then do the following calculation, it will give you the average transfer rate in MB/s:

 

size_of_file_in_GB x 1024 / transfer_time_in_seconds = transfer_rate_in_MBps

[dsjc]

   

To get transfer rates at the end of copy, use robocopy.exe from the Windows Resource Kit. Good tool for benchmarking and it is much faster then Explorer shell.