Flash card reader vs. direct USB connection

Archived from groups: rec.photo.digital (More info?)

For my old Canon S30 that uses CompactFlash, I used a
USB 1.1 card reader ("PIO Travel Flash 6 in 1 reader" ) to
transfer data to and from the card.

I was able to copy a 15 MB file to the SanDisk 128 MB card
in about 44 seconds.

Then I bought a Pentax Optio 750Z using SD cards and I
bought a Lexar 1GB card for it. It seemed slow, so I timed
it and found it took 104 seconds to transfer the same file,
less than half the speed of the CompactFlash card. The
32 MB card that came with the camera was even slower,
135 seconds.

Thinking I had gotten really slow cards, I decided to try one
more test. I connected the USB cable (still USB 1.1) directly
from the camera to the computer, and now the same file
transferred in 22 seconds!

I'm curious about all this. Does anybody have a theory as
to why the card reader is so much slower than the direct
camera <-> computer interconnect?

Thanks.

Alan

Archived from groups: rec.photo.digital (More info?)

Alan Meyer wrote:


> I'm curious about all this. Does anybody have a theory as
> to why the card reader is so much slower than the direct
> camera <-> computer interconnect?

Dunno... I find my Belkin 6-in-1 reader noticeably faster with my CF
card than plugging my Digital Rebel in directly (I haven't timed them,
but the difference is very obvious). The port on the computer is USB
1.1 only, so there's that keeping things on an even footing...

Archived from groups: rec.photo.digital (More info?)

Matt Ion wrote:
> Alan Meyer wrote:
>
>
>> I'm curious about all this. Does anybody have a theory as
>> to why the card reader is so much slower than the direct
>> camera <-> computer interconnect?
>
>
> Dunno... I find my Belkin 6-in-1 reader noticeably faster with my CF
> card than plugging my Digital Rebel in directly (I haven't timed them,
> but the difference is very obvious). The port on the computer is USB
> 1.1 only, so there's that keeping things on an even footing...

My connection from the computer dock is only USB 1.1, while my card
reader will run at USB 2.0 speeds. It is MUCH faster, limited, I
suspect, by the speed of the SD cards I have.

Archived from groups: rec.photo.digital (More info?)

I thought that might be the case, but there is some countervailing
evidence.

1. My computer is USB 2.0, but the camera manual says
it's USB 1.1.

2. The CompactFlash card was more than twice as fast as
the SD card on the same USB port, although still not as
fast as the direct camera connection.

I was wondering if it had something to do with the SD card
interface. I've heard that SD cards have no intelligence in
the interface and that CF cards do. Maybe the computer had
to send commands to the card over the USB to get each byte
or word, but when connected to the camera, the CPU in the
camera did the hard work and fed data at a higher rate to
the computer.

Pure speculation though by an ignoramus in these matters.

Alan

"Bill Hilton" <bhilton665@aol.comedy> wrote in message
news:20041208172249.10502.00001119@mb-m25.aol.com...
> >From: "Alan Meyer" ameyer2@yahoo.com
>
>>Does anybody have a theory as
>>to why the card reader is so much slower than the direct
>>camera <-> computer interconnect?
>
> It's a safe bet that the reader is USB 1.1 ... I tested a 1 GB card with 926 MB
> of data and downloads ranged from about 18 minutes with the Lexar Jumpshot card
> that comes with a Lexar flash to 3:30 with a $20 USB 2.0 card reader, or about
> a 5-6x speed difference, even though you feel your camera is USB 1.1.
>
> This 5-6x improvement is in line with the times you got with your readers vs
> the direct connection. If you get a new reader make sure it says "USB 2.0
> compatible" on the box.
>
> Bill
>
>>For my old Canon S30 that uses CompactFlash, I used a
>>USB 1.1 card reader ("PIO Travel Flash 6 in 1 reader" ) to
>>transfer data to and from the card.
>>
>>I was able to copy a 15 MB file to the SanDisk 128 MB card
>>in about 44 seconds.
>>
>>Then I bought a Pentax Optio 750Z using SD cards and I
>>bought a Lexar 1GB card for it. It seemed slow, so I timed
>>it and found it took 104 seconds to transfer the same file,
>>less than half the speed of the CompactFlash card. The
>>32 MB card that came with the camera was even slower,
>>135 seconds.
>>
>>Thinking I had gotten really slow cards, I decided to try one
>>more test. I connected the USB cable (still USB 1.1) directly
>>from the camera to the computer, and now the same file
>>transferred in 22 seconds!
>>
>>I'm curious about all this. Does anybody have a theory as
>>to why the card reader is so much slower than the direct
>>camera <-> computer interconnect?

Archived from groups: rec.photo.digital (More info?)

In article <YDdwd.8760$Wm4.8395@fe07.lga>, rphunter@charter.net says...
> Alan Meyer wrote:
> > I thought that might be the case, but there is some countervailing
> > evidence.
> >
> > 1. My computer is USB 2.0, but the camera manual says
> > it's USB 1.1.
> >
> > 2. The CompactFlash card was more than twice as fast as
> > the SD card on the same USB port, although still not as
> > fast as the direct camera connection.
> >
> > I was wondering if it had something to do with the SD card
> > interface. I've heard that SD cards have no intelligence in
> > the interface and that CF cards do. Maybe the computer had
> > to send commands to the card over the USB to get each byte
> > or word, but when connected to the camera, the CPU in the
> > camera did the hard work and fed data at a higher rate to
> > the computer.
> >
> > Pure speculation though by an ignoramus in these matters.
> >
> > Alan
> >
> >
> >
>
> Alan,
> My SD cards transfer much faster on a USB 2.0 interface than on USB
> 1.1. Probably it is the fault of the particular card reader, or card
> you have. Usually it is the camera that limits the transfer rate.
>
>
>

My 2 cents on this thread:

Card readers are CHEAP!!!
Even GOOD card readers are cheap when compared to cameras.

Im my home there are 6 computer systems (3 are just doing cancer research on
a neural net the rest are for daily use) and I have purchased a card reader
for each computer.

Reason 1. Usually, but not allways the card reader is FASTER

Reason 2. Two cats and a dog with the ability to pull the camera off the
counter/table/desk if they get into the camera cord leading to the computer.

Reason 3. Most of the time when I get done shooting and finally get to off-
load the pictures, Im dealing with 3 or more cameras and as many as 10 or 15
full cards of different types (Memory sticks, CF cards, SD cards, and even
some XD cards. Its MUCH easier to use a 6 in one or eight in one card reader
than to chunk the cards into and out of the camera.

All three of these reasons may not apply to everyone, but Im willing to bet
that two of them apply to any given home situation..

For myself I only needed reason number 2 to justify the expense of a card
reader every month 'till I had one on each system.

HELPFULL HINT: I keep my card readers "Velcro" mounted to the side of the
desktop systems and one "Velcro" mounted to the top of my laptop. Extra cord
is looped and tie=wrapped to keep it out of the way.


--
Larry Lynch
Mystic, Ct.