From my original email to Paul:
Could you guys help me out? I will get it sent to PJRC if you are out of ideas.
https://drive.google.com/file/d/1PQAKS59tvtcgTyPdpVtSjnxV05DbNbP2/view?usp=share_link...
I was asking about the best way to initialize the SD card and how I could get max performance out of it. I also had asked if overclocking the Teensy itself (not the SDIO) would make any difference.
As you said, that definitely sounds challenging. I don't write linker scripts so I can't try.
Also I've wanted to talk about #1 and #2 again. I tried using the SdFat_Usage sketch and the only begin() functions which...