Got a reply from Sandisk re my 64GB card.
Please allow us to confirm that your Ultra 64GB microSD card seems to be a genuine SanDisk product and it is already registered with SanDisk for warranty purposes.
What is not clear from your email is the format of the card. A 64GB card needs to be formatted in exFat; Fat32 can give size limitations, like the one you are facing. Do you have the options to format your card in exFat? You can choose the format you prefer during format process.
If your Dashcam requires Fat32 this means that your Ultra 64GB card is not compatible with it, because it has to be formatted in exFat to be recognized on its full capacity.
Please bear in mind that memory cards of 64GB capacity and above use a file system called exFAT and are labeled as SDXC (Secure Digital eXtended Capacity); SDXC cards are not backward compatible with devices that can accept SD (Secure Digital) cards, but will work in SDHC compatible readers (not SD readers) if the computer’s Operating System supports exFAT. You may read additional information on SDHC/SDXC compatibility and supported Operating Systems on the following web pages:
SD/SDHC/SDXC Specifications and Compatibility
Operating Systems that Support the exFAT File System
I haven't replied to it because it's gone back and I'm getting a refund, but something isn't right. That's two Sandisk cards that have shown 27.5GB in SDformatter.
So I ordered a Samsung 64Gb and that just arrived. And guess what? It shows 26.5GB in SDformatter. There's definitely something funny here.
When first plugged in Windows 7 said it needed to be formatted - it did the same with one of the Sandisk's. So I formatted with SDformatter and it's no different. But why does it format as FAT32?
Sandisk said above that 'Fat32 can give size limitations' and I have. But how do I get it to exFAT to check the correct size in the first place?
Can someone here who has formatted a 64GB card to FAT32 and still sees 64GB tell me how they did it.
I don't think there is a fault with any of these three cards. It has to be something to do with my 2xPCs and my iMac (all using SDformatter).
Incidentally. All three cards came with an adapter and in each case I used the card with the supplied adapter.