memory card compatibility

metropical wrote:

client has an older (10ish) Sony HDR CX550 cam.
He just bought a new M1 mini.

Using the SD card he had, an older 64G (32G recognized)

The CX550 family seem to have been in released in 2010.

The SDXC specification, supporting cards larger than 32GB and up to 2TB, was only released in 2009. SDXC requires (for most purposes) an exFAT filing system, while FAT32 was standard for SDHC cards.

So it's quite plausible that CX550s can't recognise SDXC cards properly, and will attempt to format them with FAT32 - imposing a 32GB usable limit.

Reformatting the 64G card (which must be SDXC) should recover the lost capacity.

The SD Association provides a low-level formatting tool intended to optimise formatting for the internal card organisation, and, if requested, erase the entire card (reducing delays due to block erasure on-the-fly):

• https://www.sdcard.org/press/thoughtleadership/the-sd-memory-card-formatterhow-this-handy-tool-solves-your-memory-card-formatting-needs/
• https://www.sdcard.org/downloads/formatter/

C10 40MB/s, it took forever to mount thru the cam and then xfer files via iMovie 10.
The xfer wasn't bad, but the mount time was 3 or 4 minutes.

Figure he's better off putting the SD card from the cam into a newer reader and direct connect to the M1 to import files.

That reader should work fine - and give decent performance with faster modern cards.

But I can't figure out if the newer Ultra SDHC or Extreme Pro SDHC will be compatible with the CX550.
Should it be, or is there a way to find/figure that out?

They should both be fine for the CX550. They are both SDHC cards, so the old camcorder should recognise them fine, and they're both fast enough for the CX550.

The "Extreme Pro" card can guarantee much higher write speeds, and so is compatible with a wider range of modern equipment, but on modern equipment the 32GB capacity could be a limiting factor at high bitrates.

Any SDHC card marked "C10" or "U1" (or above), or "V10" (or above) should be fine. I expect either of the cards you mention will work. "UHS-II" cards - which have an extra row of contacts to  allow faster transfers - would work too - the extra contacts are simply ignored in non-UHS-II card slots.

The maximum bitrate recorded by the the CX550 family seems to be 24Mbit/s = 3MByte/s. So a U1, C10 card,such as the "Ultra SDHC" you mention, which is rated to support 10MByte/s continuous writes should be entirely adequate. The "Extreme Pro SDHC" card is a U3, V30 card, supporting 30MByte/s continuous writes.

Explanation of SD card speed ratings/markings: https://www.sdcard.org/developers/sd-standard-overview/speed-class/