Kicking off the concise reviews is the 4GB CompactFlash card from Crucial. While itâ€™s certainly clear that the readers and the type of data are influencing the speeds of all the cards, this seemed to come off the worse. With both card readers it took over 5,200 seconds (almost 90mins on average) to write 1.01GB of data consisting of 4,139 mixed files in 697 folders to the card (thatâ€™s around 0.2MB/s).
This leads us to the assumption that there was either something seriously wrong with the card or that the onboard controllers/algorithms quite simply did not like receiving the multiple directory structure. Crucial states a minimum transfer rate of 3MB/s which in itself is not the quickest of the manufacturer quotes (a rating of 20X), but at this kind of speed we doubt weâ€™ll be using this card as a portable form of general data storage.
The card faired a little better when transferring 1.01GB of images in a single folder reaching a write speed of 1.7MB/s, but this was still some 3MB/s down on the next slowest CF card.
As for read speeds, the Crucial card was pretty much up there with the others - 5.4 MB/s for the multiple folders test with the SanDisk reader and 2.6MB/s for the Crucial reader. Thatâ€™s about an average wait of 190 seconds and 390 seconds respectively â€“ quite a marked difference between the two readers. But donâ€™t be fooled by the numbers. If you look closely at those graphs, itâ€™s almost certain the readers were causing a read speed bottleneck in the multiple folders test. Thatâ€™s because all of the write speeds were closely matched for those particular tests.
However, when using the SanDisk reader to transfer the single folder consisting of 1.01GB of images to the PC, unfortunately this is the slowest card on test at 5.1MB/s, translating to an average wait of 200 seconds. It also came bottom of the bunch when tested in the Canon EOS-1D Mark II, maxing out at 2.2MB/s.
Ranked last across all of the tests, in both average read and write speeds, the Crucial 4GB CompactFlash is difficult to recommend. At just over Â£90, itâ€™s also not the cheapest, but a lifetime warranty is stated.