Thursday, July 28, 2011

UDMA CF Card and Reader Speed Tests

Here's a couple of quick tests of the Transcend UDMA CF Card (Yellow) and the Datafab UDMA CF Card Reader.

I'm not a spray-and-pray type of shooter and almost never use continuous shooting mode, but while shooting events I've run out of space on my 4GB CF Card on two occasions now.  I thought about getting a larger capacity CF card.  As I was researching which card to get, I read about faster UDMA CF cards.  I remember reading about UDMA cards previously but I was not interested because I didn't think I would have use for the higher speed.  But then I thought about how it takes me a couple of hours to import photos from a single 4GB card and read how it took some reviewers only minutes to copy their photos.  That would be a welcome benefit.

I decided to get the Transcend 600X UDMA CF Card (16GB, Yellow) and the Datafab UDMA CF Card Reader.  I was somewhat concerned that a few reviewers of the Transcend said they've lost images.  But then again no brand appears completely immune from such catastrophic failure (I have a 1GB SanDisk SD card that has failed and doesn't work anymore).  In my opinion, the surest protection is to have a camera that has two memory card slots such as the Nikon D3, D300S or D7000.

Anyway, I got the Transcend yesterday and I did some tests to see the improvement in continuous shooting speed and the photo import speed.  For reference, my current CF card is a SanDisk Ultra II 4GB and I have an old USB CF card reader.

On a Nikon D300, using 1/250 shutter speed, 160 ISO, manual focus, in Raw mode, I got around 21 shots at the full 6fps rate before the camera slowed down.  After that it shot at a bit less than 3fps (78 shots in 26.5 seconds)  and didn't slow down any further after that.  I was able to get 89 shots in 30 seconds.

By comparison, with my SanDisk Ultra II (claimed to be 15MB/s), under the same conditions I got 16 shots at full 6fps burst mode, then it slowed down to 1.5fps (41 more shots in around 27.3 seconds, for a total of 57 shots in 30 seconds).

My older Nikon D70 could not take advantage of the higher speed of the Transcend. Using 1/250 shutter speed, 200 ISO, manual focus, in Raw mode, I got 3 shots at 3fps burst mode, then 18 more shots at a little more than 1 fps (18 more shots in 14 seconds).  I got the same performance from my SanDisk Ultra II.  That's fine with me because I was planning on keeping the SanDisk Ultra II for the D70 anyway.

Using an identical scene with the D300 I took 100 shots in Raw.  It turned out to be 983MB in the Transcend and 984MB in the SanDisk.  Close enough.

I uploaded each card to Lightroom 3 using Copy only (not convert to DNG), with render previews set to embedded and sidecar only.  My computer is an old laptop (AMD Sempron 2Ghz with 3GB RAM running 32-bit Windows Vista home basic) and I was writing to a Western Digital My Passport 500GB portable external hard drive.

On my old CF card reader, it took 20 minutes to download 50 images (I ran out of patience waiting to import 100 images), not counting the time it took to fetch previews.  The Ultra II likewise took 20 minutes to download 50 images.  So copying 4GB of photos takes me 2 hours and 40 minutes with either card.

Using the Datafab USB 2.0 UDMA Reader, however copying the 100 raw photos from the Transcend took just 3 minutes 37 seconds.  With the SanDisk Ultra II, it took 4 minutes 38 seconds.  Needless to say, it's a tremendous improvement and I'm very pleased with this new card reader.

The Transcend has impressive speed in continuous shooting mode, but didn't make that much of a difference when importing photos.  The Datafab reader on the other hand was an order of magnitude faster than my old CF card reader.  In retrospect I probably would have just bought the faster card reader and saved some money with a slower CF card.  At least the Transcend wasn't that much more expensive on an absolute basis compared to other 16GB cards.

I still haven't used the Transcend card in real shooting conditions.  I'll update this review after a couple of months or if anything goes wrong with the Transcend card (or the Datafab reader for that matter).


  1. That's very interesting, my camera only works with SD cards, and I already had three Kingston 8GB Class 4 (i.e. writing speed > 4 MB/s) cards, and my camera's manual recommended at least Class 6 cards for video recording but I found the Kingston Class 4 cards were faster than they are rated and worked fine.

    In an attempt to increase the low 6 frames RAW buffer of my 550D I bought two Class 10 Transcend cards, an 8GB and a 16GB, but there was almost no improvement, however with my 60D it can clear it's buffer much faster with the Class 10 cards.

    Regarding copying to PC, with the Class 10 cards and a Kingston card reader, the copying speed is ~ 22 MB/s, which means that I can clear 4GB in almost 3 minutes.

    I wonder how you had the patience to wait 2 hours for copying your memory card using the old method. Glad you got a much faster one. :-)

  2. Actually, it was much worse than 2 hours because I was converting to DNG and I used to render full 1:1 previews in LR. I used to just set it up before going to sleep. As for how I put up with it, I just thought it was normal... :))


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