eSATA Hard Drive Link Speed

I've got a Thermaltake eSATA/USB enclosure with a seagate 1TB 7200.11 hard drive connected to my Acer Travelmate 8200 via a Rosewill (Silicon Image 3132) eSATA expresscard/34 adapter. Everything is rated to work at SATA II, or 3.0GB/s.

I opened up device properties and it shows that the host and the device are running at 1.5gb/s.

I updated the driver from the silicon image website, but nothing changed.

Advice?

 

I believe that 1.5Gb/s is about 150MB/s, and the hard drive itself doesn't perform to that speed (maybe around 130MB/s), so while 1.5Gb/s comes close, it is not a bottleneck nor any real problem.

Sorry for no real help, but I just wanted to write that for your information.

 

Yeah I realize that but I went out of my way to get a SATA II expresscard and enclosure so that I could get the most potential.

As it turns out my internal drive is a Seagate 5400.2 which is SATA I, so I'm thinking the motherboard only supports that. Going to call acer and find out.

 

Well i don't think it's because of your motherboard as the express card is external so to say.

Maybe it's the cable that's provided, or maybe even the HDD inside the enclosure still has the jumper on SATA I mode, as commonly all internal 2.5/3.5" SATA HDD's does have from the beginning.


Anyway, what's the bother? There is no benefit with making it SATA II with an external HDD anyways. Nothing to achieve

 

Well I had the thought originally to basically make it perform as well as an internal hard drive, so that I could run programs and transfer files very quickly. That's why I went with eSATA.

From my experience though...I can't even tell a difference between being connected via USB or eSATA. Not sure if this is normal...

I made sure to remove the jumper . Why do they even have SATA II if there is nothing capable of even using SATA I's capability?

 

Run hdtune using esata connection.

Then run hdtune using usb connection.

Then you should see the difference, unless the hdd in the enclosure is super slow.

 

Interesting!

I wonder why the external burst speed is so much lower than the internal. I don't even know what that means, but yeah it stands out.

Also why do the sata taper off but the usb stays constant?

Internal Drive (Seagate Momentus 5400.2)


External USB (Seagate 7200.11)


External eSATA (Seagate 7200.11)

 

That's cause on USB the hard drive transfer is limited by the USB transfer rate, which looks like 32.4MB/sec on your system, while on eSATA it isn't.

Look at the numbers on the graph again.

 

Oh yeah I see the correlation between the internal and the usb. There must be a link there somewhere.... idk.

why do the others taper off anyway?

and are those numbers good or bad?

 

Huh?? You can't compare the first result with the others really. The first is a different drive. The 2nd and 3rd uses same hard drive. It's the number 1 rule of benchmarking, Keep the hardware similar as possible when comparing.

Internal Drive (Seagate Momentus 5400.2): This is a notebook drive, slower than desktop drives.

External USB (Seagate 7200.11): External desktop hard drive on a USB connection, the speeds don't taper off because the highest transfer rates are limited by the USB connection

External eSATA (Seagate 7200.11): External desktop hard drive with a eSATA connection. The hard drive max speeds aren't limited by the connection anymore.

Why does it taper off??

Think of hard drives as LP players(yes those really old players with diamond heads to read the LP disks). Hard drives work the same way. The speeds taper off since it accesses data faster on the inner edge of the disk than the outer edge.

 

Isnt the outer edge faster b/c the disk is taking the same amount of time to spin 360degrees however on the outer edge more distance is being traveled hence faster?

 

the outer edge of the harddrive platter is the fastest part. This is becase of centrifugal motion. If the drive is rotating at 5400rpm, and files are being written on the inner part of the disc, where the distance may be like 0.5" from the center of the platter. Files being written to the outer 2.5" part of the disc is faster, because for every rotation the disc is moving further.
Okay, that maybe a bad example
If you look at a tire spinning, the center of the tire barely spins at all because it has a fixed center point. if you look at say the goodyear text on the outer part of the tire, you will not be able to read it since it is moving so fast. The larger the distance from the centerpoint, the faster the data transfer is.

K-TRON

 

Like i said...

Mormegil83