USB 2 speed

ajm

ajm

ajm

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I have searched and not found the answer to this.How long on average does it take to transfer a 700mb file to a usb 2 pen drive? I don't know if my drive is working at it's full speed as it is taking about 8 minutes.
 
USB2 is max 480mbps iirc

but it does depend on CPU and memory I would have thought as the system is most likely working on more than one thing at a time.
.
 
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1MB = 8Mb

480 / 8 = 60MB/s

700 / 60 = 11.667 seconds

But I doubt you'll ever see USB hit 480MBps. :)

edit from wikipedia

* Devices marketed as "Full Speed" or "2.0" may not be capable of the current fastest speeds. Only the terms "Hi-Speed" or "480 Mb/s" have a clear, honest, definite meaning.
* Hubs, even Hi-Speed hubs, serving a number of non-hi-speed devices, are likely to divide up a total bandwidth of 12 Mb/s for such devices, which might slow them down.[1]
* Hi-speed devices are advertised as "up to 480 Mb/s", but don't actually operate at that full theoretical (60 MBytes/s) data throughput rate. The maximum rate currently (2006) attained with real devices is about half, 30 MB/s.[2] Most hi-speed USB devices typically operate at much slower speeds, often about 3MB/s overall, sometimes up to 10-20 MB/s.
Click to expand...
 
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As all these bits,bytes and MBps are all confusing to me even using the converter link by Admiral Huddy. I know this is really cheeky but could someone work out the estimated time for a 700mb file at usb 2 full rate? :o
 
Zogger has, it's about 11.7 seconds.

If you say it takes about 8 minutes, that equates to about 1.5MB/s which is about 12Mb/s which IIRC is closer to USB1 speeds.
 
480MBps is the USB2 interface speed. The fastest speed that the USB2 interface can go.
If the USB stick is only rated at 1.5MBps then that's as fast as it will go on any interface.
 
The USB stick is supposed to be usb 2is there any other way i can test this for sure? Also to test my pc's usb ports which are also supposed to be usb 2.
 
The posts above are misleading because the guys are using the USB2 specification to calculate average times. You should look at your USB drive's spec sheet (see the manufacture's webby), this will give you a better indication of how your drive should perform. Here's a example of 2 different drives:

TwinMOS USB2.0 Mobile Disk
7MB sec writing
19MB sec reading

Corsair Flash Voyager
16MB sec writing
33MB sec reading

Big difference, but they are both USB2.0!
But beware, I'd say these figures are based on a max speeds. Average speeds would be slower.
Bear in mind, transfering a large number of small files will take longer than transfering one large file.

I have a 2GB Transcend JetFlash USB 2.0 drive. The drive claims:
8MB sec writing
12MB sec reading

In reality I get:
5-6MB sec writing
10-11MB sec reading

Real World Test
2mins (roughly) to transfer a single file (695 MB (729,581,568 bytes)) from my harddrive to my USB jobby. - this is a write test.
1min (roughly) to transfer a single file (695 MB (729,581,568 bytes)) to my harddrive. - this is a read test.

I utilised USB2.0 ports for this test. My system was idle apart from the transfer job. -the rig used was my work PC (not my sig), but this is a relatively decent CAD workstation.
 
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Very well explained unde4d .

On the website it shows..

* 18.9 MB/s for Read
* 11.3 MB/s for Write

but on the packet it came in it shows..

Reading speed 1000kb/s[8mb/s]
Writing speed 9200kb/s[7mb/s]

Which one should i go by?
 
ajm said:
Reading speed 1000kb/s[8mb/s]
Click to expand...
typo?

I'm not sure why the packaging & website details would differ. Perhaps the website is listing specs of a revised version of your drive.

I'd hazard a guess & say that your max speeds are the ones on the package. Writing should be twice as slow as reading (or there abouts), so a worst case scenario for you is: 7mb/s reading, 3.5mb/s writing. If you are writing a 700MB file, i'd guess it would take about 4 minutes.
 
@unde4d

writing a 700MB file, i'd guess it would take about 4 minutes.
Click to expand...
for some reason i am not getting even close to that.It is more like 8 minutes.Does that mean i am close to usb 1 speed or may there be another reason?
 
Are the ports on your PC usb2? If you are using your header ports on the ront of your case, try some ports on the rear i/o panel. Perhaps you should check that your PC's usb ports are ok - reinstall your usb drivers.
 
@unde4d
Yes my ports are usb 2.Thanks i will try some ports on the rear and reinstall my usb drivers.
 
If reinstalling the drivers doesn't help, I'd try calling the manufactor.


>>About Firewire
You can't get Firewire Flash Thumbdrives (or atleast I'm not aware of them). You can get Firewire External Harddrives, and they might be faster than USB, but they are generally more expensive. :(

But always remember, the device you connect to your PC (whether its USB or Firewire) will have it's own spec sheet, and the values in their spec sheet will tell you how the device should perform - dont just expect USB/Firewire Specification Speeds.
 
I tried the rear usb ports and it was still the same.I don't know how to reinstall the usb drivers as there is no option for this.Any advice welcome :)
 
My USB2 flash drive always takes longer on transfer files on my computer, usually 2 mins to fill it up (1GB) but always takes around 4 mins on mine. Now it keeps saying this device can perform at USB2.0 speeds. Need to get a new one anyway, what 1GB+ one do people reconmend?
 
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