V. Basic question but...does reading an SD Card through an adapter slow it down?

Discussion in 'Hardware Discussion & Support' started by eatingrich, Apr 21, 2011.

  1. eatingrich

    eatingrich New Member

    Joined:
    Nov 9, 2004
    Messages:
    161
    Likes Received:
    1
    Trophy Points:
    0
    This is a very basic question but I've not been able to find an answer for it - does reading an SD Card through an adapter, either like a mini-USB pen or a micro-SD card being read through an SD Card adapter, slow it down?

    I just wondered as I have some spare mini-sd cards I've been using as storage and use them via USB adapters and the like.

    It leads me on to my other though, which is why would speed be capped around 500kb/s when advertised speed is in the MB/s range? I noticed this when copying information around and the speed never rose above 500kb/s but shouldn't it have been faster? Where is the bottleneck? The card, the adapter, or something in the computer?

    Cheers. :)
     
  2. shaman9876

    shaman9876 New Member

    Joined:
    Oct 15, 2002
    Messages:
    80
    Likes Received:
    3
    Trophy Points:
    0
  3. eatingrich

    eatingrich New Member

    Joined:
    Nov 9, 2004
    Messages:
    161
    Likes Received:
    1
    Trophy Points:
    0
    Cheers for the links - you may be right re the adapter. I don't think it should be as I seem to remember sending the first one I got back when it was USB1 and getting a USB2 one, but it would make sense unless there was a bottleneck with my PC somewhere.

    I basically just wondered if using a micro-SD card through a standard SD Card adapter (you know, looks like an SD Card but you slot your micro-SD card in) would slow it down or if it should be fine as long as its USB 2.

    Thanks again! :)
     
  4. shaman9876

    shaman9876 New Member

    Joined:
    Oct 15, 2002
    Messages:
    80
    Likes Received:
    3
    Trophy Points:
    0
    The adapter would not make a difference. Think of it like a gender changer for a cable. It just changes the pin layout so that it will read on the standard size SD reader.

    As to the usb pen if it is usb 2 it should have higher then 500kb/s. Maybe something is wrong with it. Can you try it in another pc to see if is the same speed on it. other then that I have no idea. Maybe somebody else can help..


    sorry about the second link that was supposed to link to a usb speed chart not the sd chart which is not needed now...grr.
     
  5. Matth

    Matth Flash Banner Hater

    Joined:
    Jun 22, 2002
    Messages:
    3,560
    Likes Received:
    49
    Trophy Points:
    58
    Yep, size adapters are passive, though of course, an adapter doubles the chance of a bad contact, though that would normally mean failure, rather than speed loss.

    USB 1.1 maxes out at 1.5MB/s, so with overheads and other device traffic, that could mean 500kB/s

    Othert possibility, the reader doesn't like the card - I have an SD card which is slow in the sytem built-in reader, but works at cracking speed in a pound store USB reader (Signalex model, which the card fits into making a rather bulky USB stick)
     
  6. Tipstaff

    Tipstaff Well-Known Member

    Joined:
    Jul 22, 2002
    Messages:
    9,318
    Likes Received:
    914
    Trophy Points:
    123
    Just to clarify something. Are all the SD cards standard SD, or do they included SDHC or SDXC too? What about the card reader/usb adapter/s you are trying to use? Do they support those formats, or just SD?

    While all readers "should" be able to read SD the same cannot be said for SDHC or SDXC. Some cannot (especially SDXC which is newest of the bunch). However, some readers that can only read SD cards can read SDHC, but at a reduced speed. Also, given that both a built in card reader and a USB external reader are the same thing (some internal are straight USB readers while some are bridged via a chip) they both work on a controller, and those can fail. Some will just stop working, while some can permanently switch to a slower USB 1.0/1.1 compatible speed.
     
    Last edited: Apr 22, 2011
  7. Judas

    Judas Obvious Closet Brony Pony

    Joined:
    May 13, 2002
    Messages:
    38,583
    Likes Received:
    944
    Trophy Points:
    138
    not all adapters are created equal..

    and the quality of the Adapter and the SD card itself.... will determine that ...
     
  8. eatingrich

    eatingrich New Member

    Joined:
    Nov 9, 2004
    Messages:
    161
    Likes Received:
    1
    Trophy Points:
    0
    Thanks for all the replies guys.

    I think the one I'm using in my laptop is 8GB micro-SD. If it's above 4GB doesn't that make it SDHC? The laptop is new so it's reading it fine I think.

    My adapter is quite old (this is different to the internal card reader my laptop has) so I think that's probably the problem.

    Might be switching to USB1.1 for some reason. It's not a huge issue but I just wondered if there were anything specific I should look out for as I was quite surprised at how 'slow' it was at that point.

    Maybe a new USB pen is the way to go! Thanks again!
     
  9. Tipstaff

    Tipstaff Well-Known Member

    Joined:
    Jul 22, 2002
    Messages:
    9,318
    Likes Received:
    914
    Trophy Points:
    123
    Technically yes, any card above 4GB would be an SDHC card, but just to note, there are 4GB SD and SDHC cards.
     
  10. letsa

    letsa New Member

    Joined:
    Jan 22, 2014
    Messages:
    1
    Likes Received:
    0
    Trophy Points:
    0
    Bumping this a bit, this page has good SEO. :)

    Just to add that the adapter used DOES make a difference. I got a cheap tiny Chinese microSD to USB adapter (advertised as USB2.0 but clearly wasnt), which wrote to my Class10 microSD at ~0.8MB/sec. When I used a proper (multi) USB Cardreader in the same port instead with the same microSDcard, the transfer speed jumped up (to about 6.5MB/sec). Quite a difference for something that should only rewire ports. Perhaps there's an internal controller chip that can't cope with the bandwidth.
     
  11. Takaharu

    Takaharu Unus offa, unus iuguolo

    Joined:
    Aug 31, 2009
    Messages:
    3,331
    Likes Received:
    328
    Trophy Points:
    108
    I think that the question was referring to a micro-SD to SD adapter, rather than a USB card reader.
     

Share This Page

visited