= 19th Aug 2022 =

Using:
 * Macbook Air M2 (2022)
 * Apple USB-C Digital AV Multiport Adapter
 * Lexar USB 3.0 SD/CF card reader (USB-A)
 * Blackmagic Disk Speed Test v3.4.2

Writing to root of each card, 5gb test file.

||                                                   || Write        || Read         ||
|| (SD) Sandisk Extreme 64gb  90MB/s, V30, UHS-1     ||  52.8 MB/sec ||  90.4 MB/sec ||
|| (CF) Sandisk Extreme 32gb 120MB/s, VPG-20, UDMA7  || 60-64 MB/sec || 108.3 MB/sec ||

This pages suggests the limits of the D800's write speeds: https://www.cameramemoryspeed.com/nikon-d800/fastest-memory-sd-cf-card-tests/
 * 40 MB/s for SD
 * 70 MB/s for CF

This means the SD card is performing roughly as expected, and can outpace the camera. It fully delivers on its read-speed claims, which is great for getting photos from the card to the computer.

The CF card is a bit on the slow side. If you're writing in Backup mode it'll still be running faster than its SD sibling, but it could do better in the camera itself. It definitely reads faster than the SD card, but not as fast as it says it should be able to.

In both cases, faster cards won't help much in the camera, and for fast-paced shooting the D800 is the wrong tool as you'll fill its internal buffer quite quickly. One of those fancy UHS-2 SD cards would do the job though. As long as the card reader can keep up, you might move files to the computer at about 250 MB/sec.


= 22nd Aug 2022 =

Same test but with a new Sandisk Extreme PRO SD UHS-II USB-C Reader.

||                                                   || Write        || Read         ||
|| (SD) Sandisk Extreme 64gb  90MB/s, V30, UHS-1     ||  52.9 MB/sec ||  92.5 MB/sec ||

So the read speeds are a few percent faster, writes are the same - card-limited in both instances I guess. The upshot is that the reader is natively USB-C now, which is great for the new Macbook Air.


= 24th Aug 2022 =

I got a new UHS-2 SD card and an SD+CF card reader for home, let's see how well they perform.

 * Angelbird 64gb AV Pro SD Mk2 UHS-II V60 (serial: AV6A6CL)
 * Sandisk Extreme PRO SD UHS-II USB-C Reader (bought last week)
 * Lexar Pro Multicard 3-in-1 USB 3.1 Type-C reader (bought today)
 * Apple USB-C Digital AV Multiport Adapter (because I can't find my high speec USB-C-to-C cable right now, and the reader comes with an A-to-C)

||                                                  || Reader  || Write        || Read         ||
|| (SD) Sandisk Extreme 64gb  90MB/s, V30, UHS-1    || Sandisk ||  52.9 MB/sec ||  92.5 MB/sec ||
|| (SD) Sandisk Extreme 64gb  90MB/s, V30, UHS-1    || Lexar   ||  52.8 MB/sec ||  90.0 MB/sec ||
|| (SD) Angelbird 64gb AV Pro SD Mk2, V60, UHS-2    || Sandisk || 132.4 MB/sec || 225.5 MB/sec ||
|| (SD) Angelbird 64gb AV Pro SD Mk2, V60, UHS-2    || Lexar   || 131.5 MB/sec || 227.0 MB/sec ||
|| (CF) Sandisk Extreme 32gb 120MB/s, VPG-20, UDMA7 || Lexar   ||    60 MB/sec ||   110 MB/sec ||

That is phenomenally much better for an SD card! The fast card will be really nice when dumping images to the computer.

The CF result is the same as before. That means we're card-limited for performance, but we expected that already.

This all makes sense, for both SD and CF - I need a new reader and new cards to get benefits when dumping files to the computer. Both readers are equally good, at least at the speeds I've been able to test them at. Even faster cards might be able to differentiate the two readers.