A few weeks ago I told you I bought a fast flash memory card for my camera, and how I expected it to speed up my photo transfers from my camera to my personal computer. I also promised to do speed tests in a real world situation. Today, I report back that there are differences, but the differences may surprise you.

In my tests, I compared the speed to move photos and video files under several situations:

The card plugged directly into card reader slots in my computer. I tried both an external reader and one on the face of my PC.

My camera attached to the PC via USB port.

I also tested two memory cards: a high-speed SanDisk Ultra II card and an even faster SanDisk Extreme III.

These all represent ways you might move your photos from your camera to your PC. To make sure I covered my bases, I compared the internal card readers of two different PCs -- one was an 18-month-old HP desktop system running Windows XP; one was a new HP Pavilion Slimline PC running Windows Vista.

If you expected the speed of the card to make a difference, you were right -- under certain circumstances. When plugged into a fast card reader, the Extreme III was about one-third faster than the slower Ultra II, which presumably would still be fast compared with standard, less expensive cards. But on a slow card reader -- like the one on my Windows XP PC, the difference was barely perceptible while timing manually with my watch.

The real gain came when I used a faster card reader. Although HP (and most other PC vendors) don't publish the specifications of the card readers that come in their systems, the reader on the new Slimline system read the cards more than 10 times faster than my older but-not-ancient desktop PC. This tells me that HP was smart enough to realize the importance of faster card readers in households and offices with digital cameras, cell phones and MP3 players, even if the company hasn't bothered to tout the improvement.

To transfer a couple photos, the additional speed may not seem like a big deal. But when you've just realized you have to empty a 2 Gigabyte card before you can take more photos at your child's concert -- and you need to be there in a half-hour, it's a major difference. Based on my tests, you'd be able to empty your fast card through a fast reader in about 2 minutes, while emptying that same card into your PC through that slower reader can take you a half-hour. So you're faced with a choice of being on time or having a usable camera.

Using a fast external reader on my older PC also worked wonders, showing about the same improvement. In my tests I used a SanDisk Extreme 2.0 USB Reader to achieve the extremely fast results. If you have a FireWire port on your PC, you may get even faster performance from a similar reader.

Are you thinking it might be better to simply attach your computer directly by USB cord? A direct link is faster if your only other choice is to use a slow reader. I found that 590 MB took 5¹/₂ minutes to transfer this way -- compared with almost 10 minutes for the slow reader -- and only 39 seconds for the fast card in the fast reader.

Now, if only we can find out the speed of the reader on that new computer before buying it.