Thanks for the revealing review of the new Sandisk cards. I doubt you have been able to test for this, but nonetheless possibly something potential customers may need to consider - could there be backward compatibility issues with various previous generation cameras? I ask because I seem to recall (without remembering the time or the details, so this is fuzzy) that a previous version of an up-graded CF card did not perform well in certain cameras. Hence just for example, if I were to buy an Extreme 4 for my Canon 1Ds (original model now dated over 5 years), could I be facing issues?
I know I'm not Michael, but since Rob Galbraith apparently successfully tested the Extreme IV with the 1Ds
and SanDisk lists the 1Ds as a compatible device
, it seems safe to assume that there shouldn't be any problems.
From a technical point of view, I have a hard time seeing why there should be problems, unless there was a flawed design decision in the CF or SD controller hardware or software in-camera.
Basically, UDMA is a standard that guarantees that compliant devices will be backward compatible; the only effect should be a fallback to the lowest interface speeds. The problems related to UDMA in PCs have been with interface cable signalling and pin compatibility. I can use a UDMA-33 drive just fine on a UDMA-133 capable controller, and a UDMA-133 capable drive on a UDMA-33 controller.