I have a Kodak DC260 and 8MB and 48MB CompactFlash cards. I presently use USB for downloading my images:

I find that the USB port via cable takes around 2 minutes to download the 8 MB card, and 15 minutes to download the 48MB card, using the Kodak mounter.

Are external card readers significantly faster? It would seem that the I/O interface and the way the software sets up the files are both bottlenecks at different times during the process. Since USB is faster than the parallel port, it would seem like a step backwards to read a card through the parallel port. Also, why would a USB-based card reader be any faster than a USB cable to my camera?

Also, are there any PCMCIA card readers that go direct to the PC's bus (not via parallel or USB connector) and have the reader External to the PC? (I don't have any spare drive bays in my PC for an internal card reader).

-- Doug Green (dougjgreen@yahoo.com), February 27, 1999

Answers

"Since USB is faster than the parallel port..." Uh, huh. How's that new bridge you bought in Brooklyn working out? Ok, I'm sorry, but I just had to rib you a little.

While USB is the new "wunderkind" on the block I'll take my parallel port based Lexar Media Smart reader any day. I may not be able to buy a hub and connect up 255 of them at once, but it does rather neatly transfer the contents of an 8Mb smartmedia to my hard disk in under 15 seconds. That's without changing the parallel port to EPP or ECP. I'd say that was about 8X's faster than your setup through the USB port. Oddly enough that's the same ratio as the number of data lines in a parallel port compared to any Serial connection, universal or otherwise.

USB sounds great(Redmond marketing hype), but until it's more widely implemented and they actually speed it up to an acceptable level like the proposed firewire standard, it's just another shiny hubcap that kind of reminds me of that other chromed Windows feature: "Plug and Pray."

Buy a parallel port or scsi based card reader for speed. The best part with old tech, like a parallel port based device, is that you can take it almost anywhere and find a pc with a parallel port. It's also immediately compatible with most laptops, even the the older ones that are clueless about USB.

Good Luck.

-- Gerald Payne (gmp@francorp.francomm.com), February 27, 1999.

Thanks for the response - BTW, you owe me $2 from the last time you crossed my bridge in Brooklyn.

Seriously, I was under the impression that overall bandwidth of a Parallel port was around 8 MB/sec, and USB is around 11.5 MMB/sec.

I agree with you, though, that the USB software implementation seems to be WAY underperforming the theoretical performance, while parallel port software seems to be much more mature and close to the limits of the port bandwidth.

-- Doug Green (dougjgreen@yahoo.com), February 27, 1999.

Grin. You caught me. Here's my 2 bucks.

I thought, as you did, that USB would be faster, stronger, better than he was before... -whoops, that's a sci-fi channel rerun. Checking out the Faq at www.usb.org sheds some light on actual practice vs. hype:

"In practice, most hosts can reach the maximum isochronous and interrupt bandwidths with a single target endpoint. With bulk transfers, typical transfer rates are around 900kb/s to a single endpoint, increasing to near ideal transfer rates with multiple endpoints."

Or in english:

While this will eventually work with most PC's, after you spend a lot of time scratching your head and aluding to Mr. Bill's questionable parentage, it will only transfer at rates up to 900KB/sec from or to a single device. You'll only get full bandwidth with multiple devices connected to it.

In fairness, my process, from beginning to end takes 15 seconds. If that's typical for an 8MB transfer, it's something like 545KB/sec. A bit slower than USB's maximum capabilities. But still faster than it's demonstrated capability with your system(about 68KB/sec.) I think as you do, that either the software or perhaps the camera itself is the culprit. You should be doing a minimum of 10-15 times faster if you approach anything near the fully touted USB speed.

Head scratching time again. Swear at Bill or Kodak for me. :-)

For now I'll stick to the parallel port, but then again I managed to hold out and stick with IDE until SCSI was well proven(civilized)... :-)

Anybody else using USB? How quick is it for you?

-- Gerald Payne (gmp@francorp.francomm.com), February 28, 1999.

USB has a maximum throughput of 1.5 megabytes per second, or around 900 kilobytes for a single device.

Parallel port does about 1.2 megabytes/sec ECP mode. So in practice parallel port can be a little faster.

People get really confused because they often quote 12 megaBITS per sec for USB, to make it sound faster. :)

SCSI and external PCMCIA readers are available, and way faster than USB/parallel, but very expensive last I checked. Minolta used to make a cheap external SCSI reader $70 but it was discontinued.

-- Benoit (foo@bar.com), March 01, 1999.

I also bought a Lexar PC card reader and download images from full 8M compact flash card less than 20s. I think parallel card PC card is faster than USB by experiencing with it but cannot explain why.

-- T.C (thcao@ouray.cudenver.edu), April 13, 1999.

Technology	Theoretical Maximum Throughput
Apple Desktop Bus (ADB)	0.01 Mbps or 10 Kbps
Serial Port	0.23 kbps or 230 Kbps
Geoport Port	2 Mbps
USB at low data transfer rate	1.5 Mbps
USB at high data transfer rate	12 Mbps
FireWire	400 Mbps
SCSI	1-40 MBps
Fast SCSI	8-80 MBps
Ultra SCSI-3	18-160 MBps

-- Tarran Walker (tarran.walker@milkit.net), May 21, 2001.