Tips for buying memory cards

By Peter Zschunke Oct 9, 2011, 3:06 GMT

Berlin - They may be called compact flash cards, but they aren't really all that compact any more. And there are plenty of smaller alternatives to the 4.3 cm by 3.6 cm memory devices.

Memory cards are also going through the trend of miniaturisation. The selection of compact flash (SF) cards is not nearly as extensive as a few years ago.

'Until now compact flash cards have been especially interesting due to their high processing speed,' said Ichiro Ike Takagi, head of the picture division at Sony.

'But for the past two or three years, SD (Secure Digital) cards and memory sticks have been reaching those same values.'

And if speed no longer plays a role, then the compact size of the SD cards and memory sticks wins out, says Takagi. 'Then it means goodbye compact flash!'

SD cards (3.2 cm by 2.4 cm) and the memory stick Duo (3.1 cm by 2.0 cm) are both significantly smaller than CF cards. Introduced in 1994, CF cards have a storage capacity of up to 128 GB - with an online price in this size of 670 euro (903 dollars). But CF cards of this capacity do not make much sense for a lot of uses - other than recordings or HD videos.

Professional photographers prefer to carry more memory cards with smaller or middle capacities rather than one large data carrier. That means the damage is less with a malfunction.

'That doesn't always have to mean the physical loss of a memory card,' said German photographer Heiko Rost. 'Exterior influences such as moisture or heat or even magnetic fields are enough to make a memory card unreadable.' Magnetic fields for example lurk at security controls at airports.

With photography, a high writing speed of memory cards is important.

'If the memory card is just messing around in the decisive moment because it's digesting the data, then the photo at the finish, the picture of the goal of the month, the explosion of the race car in the pile of tyres - basically the decisive moment - is gone,' said Rost.

Manufacturers have defined different designations for the levels of speed. CF cards have a writing speed of up to 100 MB per second (MB/s). The common SD cards reach only up to 30 MB/s. The further developed SDXC cards (SD eXtended Capacity) get up to 104 MB/s - and eventually should push up to 300 MB/s. With the capacity, the manufacturers are aiming for 2 Terabyte (2,048 Gigabyte). SDXC cards with a capacity of 64 GB and a price starting at 70 euro are suitable for camcorders.

But you should not just test if the SDXC is supported by the desired device. 'Fast memory cards also need fast interfaces on your computer, just like fast card readers,' said Rost. Recommended also is software which can save accidentally deleted files and correct access problems which can occur through recording errors in the saving of files. Free programs for this include PC Inspector or TestDisk & PhotoRec.

SD cards are also replacing more and more the multimedia cards (MMC). The flexible SmartMedia cards and the xD Picture Cards from Olympus and Fuji are nearly obsolete.

The future belongs to the SD cards. Many laptops have an SD card reader and smartphones now come standardised with additional memory via a MicroSD card. These cards are very small at 1.1 cm by 1.5 cm but can save up to 32 GB in the MicroSDHC version. A 16 GB MicroSDHC is available online starting at only 15 euro.