The SDHC to CF card adapter showed up today. The housing is slightly larger then a standard Compact flash card but it still fits easily into a standard card reader. A few people pointed out that these adapters aren’t good for video, so i thought it would be handy to run a few speed tests with the same card reader both with and without the adapter to see how well the CF adapter works.

First lets take a look at the card’s performance in an off the shelf card reader without the adapter. The card tested is the Sandisk Extreme 30MB/s class 10 card and as you can see it performs quit well, 17.8 MB/s is more then fast enough to handle DSLR  HD video little to no problem.

I had to run this test 3 times before I could believed the results, the SDHC to CF card adapter actually manages to drop the data rate of the card by almost 2/3 the original speed. 6.6 MB/sec is horrible, those speeds are so slow that they leave almost no head room for data to be transferred. The card lasted about 10 seconds before the buffer over ran and the card dropped out in video mode on the Canon 7d.

It’s hard to believe that this adapter could do such a poor job, the SDHC card performs more then fast enough to handle HD video data rates but this adapter manages to slow the card down so much that there is little to no chance that it would work for video. I’m not sure how the designers manged to do this, but I can’t recommend this adapter for video at all, and the data speeds probably aren’t good enough to expect any kind of burst rates on the Canon 7d.

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