PerformanceBox / DriftBox units work with SD and SDHC cards - so a maximum size of 32 GB can be logged to. However, we would advise that although these large capacity cards do work with the units, the larger the card, the longer it takes to initialise when inserted into the unit. For example, a 32 GB card may take up to 2 minutes to fully initialise.
The PerformanceBox / DriftBox units use around 1.1 MB per hour of card memory - so large capacity cards are not needed.
SDHC hardware support was added in the latest version of firmware (3.0.56) as SD cards are getting harder to come by. Units running firmware which is older than this will not log to SDHC however a 4 GB card will be more than adequate, as this would capture over 4,000 hours of data!
Racelogic recommends using a 2 GB SD Card formatted in FAT, or, a 4 GB SDHC card formatted in FAT32.