Now moving on to some real world tests, and some thinking aloud about data rates -
I created a 20 minute file, 24/96, which is 659MB in size.
I transferred that to the Panasonic card in the R-44 via USB, and it took 4'34" to copy across.
According to my maths, that's a data rate of 2.41MB/s.
The required data rate of the R-44 when writing two stereo tracks is (659 x 2) / (20 x 60) = 1.1MB/s
So even though the USB data rate compared to a direct transfer to the card via a reader is very slow, it's fast enough.
However, putting the card in the card reader and transferring the file to it that way takes a mere 42" - 15.48MB/s I reckon. So that's way faster than is necessary and way faster than the R-44 seems capable of writing at.
Therefore the logical conclusion would be that there's no point in using a fast card in the R-44 (or for that matter, any other 4 channel recorder running at 24/96).
But am I missing something? Like, confusing bytes and bits? Or does the R-44 write audio data in bursts and needs a faster card for that burst speed?
I guess the next test will be to use a standard speed card and see how that fares.