SD memory card speed... in iPAQ vs in Reader attached to pc?

[Mark_Venture]

Hi, How fast are SD memory cards? Does it make a difference if the card is in the iPAQ vs a Card Reader/Writer attached to a PC?

Why do I ask... Well, I have a SanDisk 256Meg SD memory card for my iPAQ 2215. I also purchased a SanDisk ImageMate 6-in-1 Card Reader/Writer that is USB 2.0. (My motherboard, Asus P4PE, has USB 2.0 ports built in)

I tried Mazingo's free text service. It was having problems, it was not deleting files, corrupting files, etc, when synchronizing it to the SD card in the iPAQ via USB cradle, so I decided to synch it to a directory on the PC and copy the files manually to the SD card via ActiveSync with the SD card in the iPAQ.

It was taking forever! So I decided to make use of the reader/writer attached to the PC, and do the copy with the SD card in it.

It still takes about 1 hour for about 55 Megabytes. Is this right? Is SD memory that slow normally? Is it just this SanDisk media? or is there something else all together?

I know the USB 2.0 ports on my PC are operating in USB 2.0 mode because of the transfer rates I get using my portable USB 2.0 hard drives attached to those SAME exact ports (I removed the Hard drives to plug the 6-in-1 reader/writer in.) Compaired to using the hard drives attached to my laptop which has only usb 1.1 ports.

[jt3]

Hmm... that's extremely slow.

It's true that going through ActiveSync will be extremely slow. For one, your iPAQ is only USB1.1 compliant, so you won't get anywhere near USB2.0 speeds. Not only that, but ActiveSync introduces a LOT of overhead, so your speeds will be cut even further. You'll probably get 2 to 3 times the performance out of a USB1.1 card reader than with your iPAQ through ActiveSync.

A USB2.0 card reader, on the other hand, should be MUCH faster. I commonly record radio shows, and carry them around on my SD card, via a Lexar JumpDrive Trio (USB2.0 SD-based flash drive). A two hour radio show runs a little over 57MB, and it takes me just under 25 seconds to write that to my SD card. The other way is even faster, it takes about 11 seconds to copy that same 57MB file from the SD card to my computer. So, an hour for 55MB is ridiculous. I should point out that this is to a Panasonic 512MB SD card, which is pretty quick, but even so, your SanDisk card shouldn't be THAT much slower.

It's possible that your card reader isn't working right. That JumpDrive Trio costs less than $20, so you might look into one of those... if nothing else, to see if it's your card or your reader that's slowing things down. Still, the jumpdrive is SUPER portable, and I couldn't live without it, so I think that once you get one, you'll definitely want to keep it.

[Andy Whiteford]

Definitely a problem there somewhere. In my experience, Sandisk cards can be quite a bit slower than other makes such as Lexar but this time you have quoted is still extremely excessive, especially for a USB 2.0 reader. For the record I have the same reader and speeds are much faster than that. I have no figures as I'm in the office at the moment. Try moving the reader to a standard 1.1 USB port and see if there is any difference. There may be some kind of conflict with the 2.0 ports. If you have access to another SD card, try that in the reader as well in case there is an issue with your card.

[Mark_Venture]

Its looking like transfer time might be related to the fact that Mazingo's data is a bunch of LITTLE files.. i.e. jpgs, htmls, etc that are anywhere from 1k to 5k in size...

I just tried copying One Single 50 meg .WMV file to the SD card in the 6-in-1 reader attached to the PC. It took less than 2 minutes!

I guess USB starts data transfers slow and speeds up as it goes? and maybe files that small do not give it enough time to get up to full speed before it has to go on to the next file?