Esata Slower Than Poop?!

[rayzoredge 2]

Yes, what an immature subject title. No, I won't take it back.

Anyway, so we know that the wonders of SATA include a theoretical 1.5Gbps to 3.0Gbps data transfer rate capability. Silly me went out and bought an eSATA-capable enclosure for my new hard drive to be utilized with my new laptop, which has an eSATA port. Silly me connected the cables to my old eSATA-capable external hard drive to pull files off of it to be placed onto the computer so that I could copy them off afterwards (since the laptop only has one eSATA port). I dragged and dropped about 200GB of files onto the desktop, then waited in silent glee over the prospective ease and speed of backing up to my new hard drive.

I was sorely disappointed.

At first, the transfer rate started at about 10MB/s. Thinking that maybe it took a second to realize the full, awesome power of SATA, I let Windows 7 continue with its copy job. 30 minutes of constant checkups later, the transfer rate gradually climbed over time and now we're up to 20MB/s, but it just dropped now to 19.7MB/s. Needless to say, I was kind of upset about this. So I tugged on Google's pants and it seems that other people are having the same expectations but not so much the same on the results.

After some thinking, I realized that there has to be a bottleneck somewhere. Duh. So I made sure Windows 7 had proper drivers. Check. I looked up the data read/write speeds of the hard drive. Apparently there are two speeds: transfer rate from media to/from buffer and transfer rate from media to/from host... which are both way above what I'm getting for a transfer rate. So what gives? Why am I amongst the many on the Internet complaining about 10-20MBps speeds on a SATA connection? Is there something I'm missing?

Edit: I read on another forum that explains why I'm seeing slow speeds, but at the same time, it still doesn't add up.

And just to clarify, SATA's bandwidth is 3Gbit/sec, not 3GB/sec. The encoding overhead means that the 3Gbit/sec bandwidth winds up as 300MB/sec maximum data throughput.
However, no hard disk can even come close to sustaining that throughput - the best drives right now top out at ~120MB/sec.

Before I applied the firmware update to my FAP drive I would get about 35MB/sec over eSATA (and about 33MB/sec over USB). The firmware update improved this to ~55MB/sec over eSATA, but the reliability of transfers was awful, the the drive clicking and powering down and then back up.

I wasn't aware that the overhead was THAT bad (-84MBps) and I was also unaware how bad my hard drives seem to be in the sense that the "best" drives top out at ~120 MBps.

But even with this arguments explaining why we don't reach the magic number of 384MBps, why the heck am I experiencing speeds that are less than half of what this guy states for his external hard drive? Is Samsung that bad with SATA hard drives? Is my enclosure with no driver upgrade path to blame?
Edited October 22, 2009 by rayzoredge (see edit history)

[bluedragon 0]

hmm.. Thats strange.
Even the reviews I've heard say that it should be faster than the USB 2.0 specification and 10 MBps is I think like USB 1.0 or 1.1

I hope your cable is not faulty or some internal connection thats connecting the HDD to eSata converter could be functioning wrong.

Even the standard casings (normal USB 2.0) that I've used give more transfer speed than what you are telling.

and I don't think they'll make some new technology which is slower than the present technology .

If the warranty is under warranty , I'll suggest you get an RMA or something and get it changed.

Yes, what an immature subject title. No, I won't take it back.
Anyway, so we know that the wonders of SATA include a theoretical 1.5Gbps to 3.0Gbps data transfer rate capability. Silly me went out and bought an eSATA-capable enclosure for my new hard drive to be utilized with my new laptop, which has an eSATA port. Silly me connected the cables to my old eSATA-capable external hard drive to pull files off of it to be placed onto the computer so that I could copy them off afterwards (since the laptop only has one eSATA port). I dragged and dropped about 200GB of files onto the desktop, then waited in silent glee over the prospective ease and speed of backing up to my new hard drive.

I was sorely disappointed.

At first, the transfer rate started at about 10MB/s. Thinking that maybe it took a second to realize the full, awesome power of SATA, I let Windows 7 continue with its copy job. 30 minutes of constant checkups later, the transfer rate gradually climbed over time and now we're up to 20MB/s, but it just dropped now to 19.7MB/s. Needless to say, I was kind of upset about this. So I tugged on Google's pants and it seems that other people are having the same expectations but not so much the same on the results.

After some thinking, I realized that there has to be a bottleneck somewhere. Duh. So I made sure Windows 7 had proper drivers. Check. I looked up the data read/write speeds of the hard drive. Apparently there are two speeds: transfer rate from media to/from buffer and transfer rate from media to/from host... which are both way above what I'm getting for a transfer rate. So what gives? Why am I amongst the many on the Internet complaining about 10-20MBps speeds on a SATA connection? Is there something I'm missing?

Edit: I read on another forum that explains why I'm seeing slow speeds, but at the same time, it still doesn't add up.



I wasn't aware that the overhead was THAT bad (-84MBps) and I was also unaware how bad my hard drives seem to be in the sense that the "best" drives top out at ~120 MBps.

But even with this arguments explaining why we don't reach the magic number of 384MBps, why the heck am I experiencing speeds that are less than half of what this guy states for his external hard drive? Is Samsung that bad with SATA hard drives? Is my enclosure with no driver upgrade path to blame?

[rayzoredge 2]

Sorry for the late response... I lost this post and didn't think about it until more use of the eSATA feature of the external hard drive.

 

It seems that these speeds are right on the money, although I'm not sure what is causing the inconsistencies. I'm reporting that I do see faster performance, but only up to twice the speed of USB 2.0, which may or may not be correct. I looked up benchmark results and they seem consistent with my findings.

 

The inconsistencies that I found, however, note that it almost seems to "pick up speed" or "slow down" during file transfers over eSATA, like moving a variety of files from 10KB to 6GB and whatnot, either matching USB 2.0's highest speeds, going even slower than that, and then climbing back up to double the usual performance of a USB 2.0 connection. Maybe Windows 7 is incorrectly measuring the transfer rate... I don't know, but I was definitely sorely surprised to find out the hard way that eSATA, although much faster than USB 2.0, is not what I expected. Then again, I'm sure the speeds are comparable with current transfer rates of internal SATA hard drives in a desktop, now that I think of it, so this whining of mine is unnecessary and stupid.

 

In comparison:

Speed of SATA: 192 to 384 MB/s (theoretical)

Speed of eSATA: about 131 MB/s (real-world)

Speed of USB 2.0: 60 MB/s (theoretical)

 

Something else that I am finding, though, that is bit of a pain is that when I connect my external hard drive using an eSATA cable, my computer won't recognize the drive without multiple attempts of re-inserting the cable, either on the computer's port or into the external hard drive's port. Not sure if this is the fault of the cable itself, the OS, or how the port behaves... I usually end up plugging everything in, turning the hard drive on, finding out it isn't being recognized, unplugging and plugging the cable back into the computer port, THEN having it recognized. Anyone else having this issue?

[inverse_bloom 0]

Yeah i have that problem with my USB devices on Win XP. Admittedly i have at least 6 or 7 devices operating from usb hubs, but i know that isn't the issue. Its more to do with the devices themselves and something going on with XP. For instance when i open up the laptop and load out of stand by mode, i always need to reconnect that USB modem dongle to properly refresh it. Likewise with my USB Terabyte hard drive i sometimes have to do the same for that.(this is a wild guess) It sounds like on the first go the OS figures out you have a hard drive enclosure and loads the processes or drivers necessary to work with the device, but its not until the second refresh (with loaded processes/drivers or whatever from the first attempt) it can recognize that you have a "Samsung" HD in the enclosure so you can use it.I don't know the solution for this.

[k_nitin_r 8]

I'm guessing you either have a 5,400rpm drive or you are transferring a lot of small files. When transferring files, if you have a single large file the transfer would be much quicker than if you had multiple small files. Perhaps adding the files into a ZIP file would improve transfer rates because of having a single file and because of the ZIP archive compression (for better compression, you can use 7z or StuffIt). You might also want to invest in a faster hard drive if you perform a lot of large transfers between drives. You could either get a high speed solid state hard drive or a mechanical hard drive with a faster spin rate. Faster spin rates also cause more heat and more noise but the speed they deliver would make up for it.