Comparing HDD transfer rates for X-Drive II (split from EastGear's MO of X-Drive II)

[Nutcase]

Thought I should share my experience as someone who has bought the XD II with a 5400rpm drive recently. For those of you planning to buy a 5400rpm drive, you may want to reconsider if you are only going to use it as a portable drive.

Was just doing the math... USB2.0 = 480Mbps maximum transfer rate. This translates to approx. 468.75KBps. If I am not mistaken, even a 4200 rpm drive has a maximum interface transfer speed of 100MBps !!!

Even if you look at the media transfer rates, it's only 20+Mbps diff between 5400/4200rpm and the seek times are exactly the same!!! Well, I guess you get slightly better response in terms of latency, but if you are hoping that getting a 5400rpm drive means faster transfer between your memory card and the drive - forget it.

So I have been suckered (but I insisted even though the shop keeper warned me so ). Hope this helps you make a better decision.

Cheers!

 

[mrbunglez]

Thanks for the tip nutcase. i initially thought that gettin the 5400rpm disk would be good, but backed down cuz price not too agreeable la.. hahaha.. so its 4200 for me

so hows the xdrive ii serving u? good not? convenient?

 

[mpenza]

Originally posted by Nutcase
Was just doing the math... USB2.0 = 480Mbps maximum transfer rate. This translates to approx. 468.75KBps. If I am not mistaken, even a 4200 rpm drive has a maximum interface transfer speed of 100MBps !!!

erm, you're quite seriously mistaken.

480Mega bits per second = 60 Mega Bytes per second (not 468.75KBps!?!?!?!)
for info, 1 byte = 8 bits

Also, no drive can provide sustained high speed transfer all the time and 100 Mega (bits or Bytes) per second is not the right figure too.

 

[Nutcase]

Originally posted by mrbunglez
Thanks for the tip nutcase. i initially thought that gettin the 5400rpm disk would be good, but backed down cuz price not too agreeable la.. hahaha.. so its 4200 for me

so hows the xdrive ii serving u? good not? convenient?

Pleasure. So far so good. I have tried SM and CF on it and no problems so far. However, there has been 1 incident which worried me a little. The CF has about 200+ MB worth of data. however, the copying stopped at 190MB+.

I have not tried copying something > 200+MB since so I am not sure if this has anything to do with a maximum size or what? Maybe someone can confirm either way?

Otherwise - works like a beaut. I partitioned my 40GB into 10/30 to FAT/NTFS, so I am only using the 10GB for the XDrive and the other 30GB I use as portable HDD. (I transfer the HDD into my cutie casing when I am not travelling). Am very happy with it to date.

 

[Nutcase]

Originally posted by mpenza
erm, you're quite seriously mistaken.

480Mega bits per second = 60 Mega Bytes per second (not 468.75KBps!?!?!?!)
for info, 1 byte = 8 bits

Also, no drive can provide sustained high speed transfer all the time and 100 Mega bits per second is not the right figure too.

480Mb = 480 * 1,024,000 bits = 491,520,000 bits

491,520,000 bits = 491,520,000 / 1024 = 480,000 Kbits

480,000 Kbits = 480,000 / 1024 = 468.75 KBytes

Oh - its true that no drive can sustain max speed transfer, but in any case, will easily be > 480Mbps. Plus I believe I mentioned 100 MB(ytes)ps not 100Mb(its)ps

 

[mrbunglez]

wah really? if >200MB then got chance of screw up? hmmm... scary man.. maybe other users can comment, so the newbies like me don't panic unnecessarily.. hahhaaa..

and can partition somemore? cool.. how do u ensure the the data from the CF or SM gets written into the correct partition leh?

Originally posted by Nutcase
Pleasure. So far so good. I have tried SM and CF on it and no problems so far. However, there has been 1 incident which worried me a little. The CF has about 200+ MB worth of data. however, the copying stopped at 190MB+.

I have not tried copying something > 200+MB since so I am not sure if this has anything to do with a maximum size or what? Maybe someone can confirm either way?

Otherwise - works like a beaut. I partitioned my 40GB into 10/30 to FAT/NTFS, so I am only using the 10GB for the XDrive and the other 30GB I use as portable HDD. (I transfer the HDD into my cutie casing when I am not travelling). Am very happy with it to date.

 

[Nutcase]

Originally posted by mrbunglez
wah really? if >200MB then got chance of screw up? hmmm... scary man.. maybe other users can comment, so the newbies like me don't panic unnecessarily.. hahhaaa..

and can partition somemore? cool.. how do u ensure the the data from the CF or SM gets written into the correct partition leh?

You dun have to worry about writing to the correct partition. XD II only recognise the 1st FAT partition. So any other partition you make will be ignored by the XD. But of course, when you transfer the HDD into you proper HDD casing, all partitions will become visible and accessible.

 

[EastGear]

Originally posted by Nutcase
480,000 Kbits = 480,000 / 1024 = 468.75 KBytes

The conversion from bits to bytes is not correct.
As mpenza put it, 1 byte = 8 bits

Hence,

480,000 Kbits = 480,000 / 8 = 60,000 KBytes
60,000 KBytes is approximately 60 MB

 

[Snapper]

Isn't there a parity bit or CRC checksum ?

 

[acidbyte]

Will there be some sort of verification while the files are being copied over ? At the end of the day, i don't wish to discover that the files copied over will have error or worse still, didn't got transferred over into the HDD.

Oh by the way,EastGear,i've just e-mailed you. Please check your e-mail. Thanks.

 

[mpenza]

Originally posted by Nutcase
480Mb = 480 * 1,024,000 bits = 491,520,000 bits

491,520,000 bits = 491,520,000 / 1024 = 480,000 Kbits

480,000 Kbits = 480,000 / 1024 = 468.75 KBytes

EastGear has made the corrections (see above). You must have avoided all USB 1.1 peripherals which will only transfer ~12KBps (~12 times slower than the floppy disk) according to your calculations....

Originally posted by Nutcase
Oh - its true that no drive can sustain max speed transfer, but in any case, will easily be > 480Mbps. Plus I believe I mentioned 100 MB(ytes)ps not 100Mb(its)ps

Following the correction, sustained harddrive transfer speed will easily be less than 480Mbps and a faster harddrive does help (at least for the transfer from Xbox to the PC). But as usual, the slowest component in the chain will determine the overall transfer speed.

Yup, misread the part about the B and b ;p Anyway, that's just the theoretical interface transfer speed for one of the standards (ATA-100?).

 

[Kevin]

Hi, anyone try transfer file bigger than 1 GB from PC's HDD to XDrive II's HDD say PC in W2K pro?

I bought a external HDD (3.5") casing from Korea and I get I/O error during the transfer. My MB don't have USB2.0 so I put in a USB2.0 PCI card. Not sure the problem is the PCI card or the external HDD casing? If X Drive can work, may consider getting one. Preferebly someone has tried with > 4GB file.

 

[Kevin]

Hi, Mpenza and other MAth Genius. Can you please tell me the difference in seconds for transfering 100MB file from PC HDD to external XD II HDD in 5400rpm and 4200rpm? I am lost in the formula you guys discuss!!!

 

[acidbyte]

I didn't know i had to format the HDD, has anyone tried it in Win 2K yet ?

 

[mpenza]

Originally posted by Nutcase
I believe your calculation is right! 480Mbps should translate to slightly under 60MBps. Now I know why I dropped Math for my A's!

Well - Makes me feel better to know that my 5400rpm isn't so darn useless even with USB2.0 afterall!

But can you please explain why a faster drive will help increase the sustained transfer speed? and 100MBps is UDMA

hmm... a faster rpm drive rotates the disc media faster and hence allows more data to be read per unit time.... this will increase the sustained transfer speed given that other specifications (cache, interface protocol) remain the same. Do note that data need not be stored in a sequential manner on a harddisks. A single file could be located in many different locations, hence a faster drive could picks up all the individual blocks in a shorter time.

 

[mpenza]

Originally posted by Kevin
Hi, Mpenza and other MAth Genius. Can you please tell me the difference in seconds for transfering 100MB file from PC HDD to external XD II HDD in 5400rpm and 4200rpm? I am lost in the formula you guys discuss!!!

That's just theoretical.

There're many components involved.... external harddisk performance, interface used, driver optimisation, OS overheads, internal harddisk performance, real-time file monitoring by anti-virus program, motherboard bios microcode implementation, etc. (just something I thought of) I won't be able to tell you without testing....

http://www.storagereview.com has benchmarks which could provide some reference but a brief check showed that no notebook harddisk was tested....

Here's an article on harddisk performance which you might be interested in:
http://www.storagereview.com/welcom...ew.com/guide2000/ref/hdd/perf/perf/index.html

 

[Kevin]

Thanks KC.....

 

[Nutcase]

Originally posted by mpenza
hmm... a faster rpm drive rotates the disc media faster and hence allows more data to be read per unit time....

But I thought that is represented by the media transfer rate (ie how fast data can be transfered from the media to the disc interface...

...single file could be located in many different locations, hence a faster drive could picks up all the individual blocks in a shorter time.

and this is represented by the average seek time (ie how faster the head moves from one sector to another within the disc.

If the 2 parameters we are looking at is true, then it appears that the value is the same for both 4200/5400rpm drives. :dunno:

 

[agape01]

I would like to share my experience about the X-Drive II.

The one thing that when you get a X-Drive is that you have to make sure that the drive is transferring data over. On the overall basis, it is a wonderful device to use.

What happened to me is that I went for a outdoor model shoot. The sad part is that I had lost about half of my shots because I did not make sure that the transfer was actually taking place. I didn't see the LCD screen indicating that the transfer was taking place. BTW, I was transfering a 512MB CF card all shots taken in RAW. When I got home, I realised that I had lost about half of the shots. That is the horrible part of the X-Drive. When you loose information, you just get a very bad feeling. Something like you just want to kick yourself.

On the other hand, I went on a shooting spree at the Cheerobics competition. This is where the X-Drive performed beautifully. I took over a thousand shots for the event and had no problems whatsoever in transferring the images.

Mpenza as well as whoever is going to the Zoo shoot on Saturday, I would gladly show you guys my X-Drive. Just got to make sure that the transfer is actually taking place as I would be shooting in RAW again.

 

[agape01]

BTW, to transfer one 512MB CF card into the X-Drive would take a little less than 8 minutes. I had actually timed it myself.