zoidberg101 -> RiData x80 du henviser til er type II kort. Så vidt jeg ved understøtter IXUS un type 1 (har ikke kunnet finde bekræftelse på Canon.dk)
CF type I - 36.4 x 42.8 x 3.3mm
CF type II - 36.4 x 42.8 x 5.0mm - altså lidt tykkere.
En anden forskel er power:
The type I interface can supply up to 70mA to the card, the type II interface can supply up to 500mA, so you can see that a type II interface is required if the card draws a lot of power.
Note that there are two different types of memory cells used in CF memory. The first and fastest is called a Sigle Level Cell (SLC) which stores 1 bit in each cell. There's also a slower (but cheaper) architecture called Multi Level Cell which stores two bits in each cell. Both technologies are getting faster, but the fastest cards are always based on SLC technology. SLC technology also uses a little less power then MLC, so that's another advantage. The main advantage of MLC is in cost per megabyte.
The real question is not how fast a manufacturer says a card is, but will an 80x card actually give you 4x faster performance than a 20x card when you use it in a camera? The answer is often "no". The speed at which data is written to the card depends on three factors. First there's the maximum write speed of the card. Second there's the maximum write speed of the camera. Third there's the efficiency of the interaction between the camera's software and the card's onboard controller. All three of these can influence the speed at which data actually gets written.
Ovenstående klippet fra Bob Atkin's site, hvor intereserede selv kan læse mere
http://www.bobatkins.com/photography/digital/compact_flash_memory_cards.html
