Digital Home Thoughts: Memory Card Shoot-Out: Four 512 MB Secure Digital Cards Compared

Overall Speed Results


Figure 8: Test results summary for all 512 MB SD cards.

The above chart indicates the cumulative total of each card – the KB/s speed of both the reading and writing tests were added together and the results show a clear winner: the Sandisk Ultra II is the fastest card overall and the winner of this shoot out. If you want the ultimate in performance, that's the card to get.

Best Bang for your Buck?
Once you factor in price, however, things get a little more complex. The Simpletech 512 MB SD card sells for as low as $98 USD in a Pricegrabber search. The Sandisk Ultra II sells for as low as $158 USD. The two Delkin cards list for as low as $97 and $222 (eFilm and eFilm Pro respectively). Let's have some fun with the math ;-) – I've never seen anyone do this before, so this might be a first. What happens when we take the overall KB/s ratings from the six tests, convert it to megabytes per second (MB/s) and compare it to the retail cost of the card? Here's what we get from lowest cost to highest cost:

$3.51 per MB/s – Simpletech 512 MB SD
$3.99 per MB/s – Delkin eFilm 512 MB SD
$4.26 per MB/s – Sandisk Ultra II 512 MB SD
$6.41 per MB/s – Delkin eFilm Pro 512 MB SD

Surprisingly, the best combination of value and price is the Simpletech card, followed by the Delkin eFilm card. The Sandisk is the performance champ, but nearly double the cost of the Simpletech card. If performance is your #1 need, the Sandisk Ultra II is the card you want. The Delkin eFilm Pro card is a decent performer, but it's 33% more expensive and 7% slower than the Sandisk Ultra II. You won't notice a 7% difference in performance, but you will notice a 33% price difference.

Final Thoughts...
Ultimately the card you pick should be based on how you'll use it. If the SD card is going into a Pocket PC or Smartphone, and will be primarily used for reading data stored on it (audio, video, programs), the read speed is more important than the write speed. If the card is going into a camera, however, write speed is paramount and you'll want the fastest card you can get your hands on even if it's more expensive.