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

eatingrich · Apr 21, 2011, 01:19 PM

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.

shaman9876 · Apr 21, 2011, 01:42 PM

Here is a chart of sd card speeds.

http://www.sdcard.org/developers/tech/speed_class/

Here is a chart for port speeds(I it is not fully updated but the information you need to figure it out is there.)

http://www.sdcard.org/developers/tech/speed_class/

My guess is one of the devices you are using is only usb 1 which is causing the issue.

eatingrich · Apr 22, 2011, 11:37 AM

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!

shaman9876 · Apr 22, 2011, 03:13 PM

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.

Matth · Apr 22, 2011, 09:34 PM

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)

Tipstaff · Apr 22, 2011, 10:53 PM

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.

Judas · Apr 23, 2011, 05:08 PM

not all adapters are created equal..

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

eatingrich · Apr 25, 2011, 02:41 PM

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!

Tipstaff · Apr 26, 2011, 05:55 AM

Quote:

Originally Posted by eatingrich

If it's above 4GB doesn't that make it SDHC?

Technically yes, any card above 4GB would be an SDHC card, but just to note, there are 4GB SD and SDHC cards.

Apr 21, 2011, 01:19 PM	#1
eatingrich HardwareHeaven Lover Join Date: Nov 2004 Posts: 159 Rep Power: 0 System Specs	V. Basic question but...does reading an SD Card through an adapter slow it down? 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. __________________ Check out my gaming blog for stuff about Windows Phone, retro gaming and Xbox - www.zombiesatemyxbox.com

Apr 21, 2011, 01:42 PM	#2
shaman9876 HardwareHeaven Junior Member Join Date: Oct 2002 Location: USA, WI Posts: 80 Rep Power: 62 System Specs	Re: V. Basic question but...does reading an SD Card through an adapter slow it down? Here is a chart of sd card speeds. http://www.sdcard.org/developers/tech/speed_class/ Here is a chart for port speeds(I it is not fully updated but the information you need to figure it out is there.) http://www.sdcard.org/developers/tech/speed_class/ My guess is one of the devices you are using is only usb 1 which is causing the issue.

Apr 22, 2011, 11:37 AM	Thread Starter #3
eatingrich HardwareHeaven Lover Join Date: Nov 2004 Posts: 159 Rep Power: 0 System Specs	Re: V. Basic question but...does reading an SD Card through an adapter slow it down? 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! __________________ Check out my gaming blog for stuff about Windows Phone, retro gaming and Xbox - www.zombiesatemyxbox.com

Apr 22, 2011, 03:13 PM	#4
shaman9876 HardwareHeaven Junior Member Join Date: Oct 2002 Location: USA, WI Posts: 80 Rep Power: 62 System Specs	Re: V. Basic question but...does reading an SD Card through an adapter slow it down? 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.

Apr 22, 2011, 09:34 PM	#5
Matth Flash Banner Hater Join Date: Jun 2002 Location: UK Posts: 3,426 Rep Power: 93 System Specs	Re: V. Basic question but...does reading an SD Card through an adapter slow it down? 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) __________________ Mary had a little lamb, Her father shot it dead Now Mary takes her lamb to school, Between two crusts of bread

Apr 22, 2011, 10:53 PM	#6
Tipstaff HardwareHeaven Extreme Member Join Date: Jul 2002 Location: Real capital of Canada: Torauna Posts: 6,773 Rep Power: 190 System Specs	Re: V. Basic question but...does reading an SD Card through an adapter slow it down? 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. __________________ Portal: The Flash Version _________________________________ Brain: So, you sacked the cocky khaki Kicky Sack sock plucker? Mr. Sackett: The second cocky khaki Kicky Sack sock plucker I've sacked since the sixth sitting sheet slitter got sick. Last edited by Tipstaff; Apr 22, 2011 at 10:59 PM.

Apr 25, 2011, 02:41 PM	Thread Starter #8
eatingrich HardwareHeaven Lover Join Date: Nov 2004 Posts: 159 Rep Power: 0 System Specs	Re: V. Basic question but...does reading an SD Card through an adapter slow it down? 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! __________________ Check out my gaming blog for stuff about Windows Phone, retro gaming and Xbox - www.zombiesatemyxbox.com