eSata VERY slow

If you want the best speed from eSATA, use a bare HDD and a combo power eSATA cable. I got a cable and silicone case for the 2.5mm HDD for about $20, and routinely get 65MB/s or more.

 

I have a GoFlex 500GB on eSATAp and other conventional eSATA devices and haven't had any notable issues with it. The only time speeds drop sharply like that are when many small files are transferred, which is normal for any type of drive.

Is this comparing with the same data set? Your numbers sound a bit inconsistent from what I usually see on eSATA. In general, eSATA numbers by far exceed USB 2.0. Most USB 2.0 drive enclosures max out at 25~30MB/s sustained.

As far as why you take a performance hit when write caching is turned off, it's quite simple -- caching allows the system to get things ready in cache memory ahead of time. Turning off that cache means controller must wait for a confirmation from the drive that the last block was done and is ready for the next, each and every time, meaning more wasted time "waiting". This is extremely noticeable when transferring lots of smaller files. Drive cache memory will help a bit with this, but the margin will depend on how quickly the drive clears the transactions.

Also, sometimes plugging a drive direct makes it go faster than a USB/eSATA enclosure since the controller chip in the enclosure is another layer that it has to go through.

 

Hi AlexF, thanks for your thorough reply!

I do get the importance of a write cache when it comes to speed (and see the dilemma when it comes to a mobile device which I would like to be able to quickly remove), but I was and still am wondering about this difference: USB 2.0 write cache off - ~25MB/s, eSATAp write cache off - ~10MB/s. I just don't understand that.

After more testing (write cache enabled due to what I just wrote) I get 45 to 75MB/s with the eSATAp Drive, which I guess I have to be fine with. And I can : )

AlexF, if you don't mind: what speed does Windows show when you transfer a file of 2 to 4 GB to your GoFlex drive? Thanks!

 

Best guess: protocol overhead.

Transferring a 6GB file to the unit from the provided 500GB 7200rpm Samsung HDD via E6420's eSATAp port with my GoFlex Pro 500GB (7200rpm) gives me a constant 75-80MB/s in Explorer. I've attached the HDTune chart: 28.7MB/s min (dips), 96.2MB/s max, 79.6MB/s average.

Since this is an NTFS-formatted partition, "Better performance" and "Enable write caching on the device" is enabled by default. This means you must do a proper "safely remove" from the system.

 

Hi AlexF, thanks a lot for your effort!

I myself transferred an 8GB file from and to the GoFlex, and reading was 70 to 80 MB/s and writing never truly settled - started at ridiculously high and possibly very untrue 300 MB/s and went down to something around 60 MB/s. That is 3x USB 2.0 and I am truly fine with it. But the HD Tune readings promise even greater values...

 

Hi All.
I hope you don't mind me tagging on the end of your discussion. It seems you all might be able to provide some valuable insight into my issue.
I've been trying to get a suitable eSATA setup rigged up to my laptops for a little while now but still have issues.

The main reason I went with sSATA as opposed to USB 3.0 is that you can't seem to get hold of USB 3.0 old style laptop PC Cards (I know about the speed limitations of the old Cardbus interface but I would be prepared to take a slight hit for compatibility sake) but you can get hold of eSATA cards. My other laptop has a 54mm PC Card Express port, USB 3.0 / eSATA adaptors are readily available.

I proceeded to make my own eSATA portable drive with an external eSATA / USB enclosure and a TOSHIBA MK1059GSM 2.5 12.5mm 1TB drive. I could get the drive to work connected up to a Lenevo Think Centre eSATA port (scored 75Mb/sec with HD Tune) but it will not work using a laptop Cardbus card (SiI 3x12 SATALink controller) / PC Express Card (Asmedia Chipset). That was with the assistance of an external 5v power supply.

Using a lower capacity seagate drive instead works fine on my laptop setups. The problem seems to lie with the Toshiba 2.5" hard drive. Some sort of compatibility problem with the laptop card adaptors. I don't have access to another 1TB 2.5" drive to re-test the configuration. Drive prices have rocketed in recent times. Maybe that's the way to go to fully verify the setup.

Hopefully drive prices will come down again and I get my hands on a nice 9.5mm compatible drive. Getting hold of 12.5mm eSATA portable drive enclosures is expensive compared to other types. I got hold of a nice enclosure made by ORICO 2598SUS3 which has the benefit of combined eSATA and USB 3.0.

If anyone has any further suggestions on getting eSATA working with the Toshiba drive on my laptops (without forking out for a new laptop) I'm all ears.

Its a shame that manufacturers have resorted to swapping out the SATA interface electronics on hard drives used in commercial USB portable drives so that you can't take them apart and re-use them!

Cheers and all the best.

 

By won't work, is it won't detect or gets errors?

Things to try:
- See if your manufacturer has a newer version of firmware for your expansion card. Most SiliconImage setups have flash-upgradable firmware.
- Try getting a 3.5" eSATA enclosure with the 2.5" drive (tests with a larger power source and different type of enclosure).

It should also probably be noted that USB on older PCs sometimes are weak and may have trouble with line-powered devices (if that's where the 5V source was from).