I have noticed an issue where using a microSD over SPI is now at reduced speed and performance in Teensyduino 1.54 Beta 5.
While using Teensy 4.0 with Audio Shield Adapter with 1.54 Beta 5, I noticed that some of my sketches had a significantly reduced speed/performance.
After running the "SDCardTest" here were my results (Teensy 4.0 with Audio Shield Adapter):
Teensyduino 1.51
Code:
SD Card Test
------------
SD card is connected :-)
Card type is SDHC
File system space is 15466.05 Mbytes.
SD library is able to access the filesystem
Reading SDTEST1.WAV:
Overall speed = 1.67 Mbyte/sec
Worst block time = 0.72 ms
24.78% of audio frame time
Reading SDTEST1.WAV & SDTEST2.WAV:
Overall speed = 1.51 Mbyte/sec
Worst block time = 1.34 ms
46.15% of audio frame time
Reading SDTEST1.WAV & SDTEST2.WAV staggered:
Overall speed = 1.51 Mbyte/sec
Worst block time = 1.02 ms
35.02% of audio frame time
Reading SDTEST1.WAV, SDTEST2.WAV, SDTEST3.WAV:
Overall speed = 1.49 Mbyte/sec
Worst block time = 1.98 ms
68.35% of audio frame time
Reading SDTEST1.WAV, SDTEST2.WAV, SDTEST3.WAV staggered:
Overall speed = 1.50 Mbyte/sec
Worst block time = 1.59 ms
54.80% of audio frame time
Reading SDTEST1.WAV, SDTEST2.WAV, SDTEST3.WAV, SDTEST4.WAV:
Overall speed = 1.49 Mbyte/sec
Worst block time = 2.59 ms
89.17% of audio frame time
Reading SDTEST1.WAV, SDTEST2.WAV, SDTEST3.WAV, SDTEST4.WAV staggered:
Overall speed = 1.49 Mbyte/sec
Worst block time = 1.64 ms
56.42% of audio frame time
Teensyduino 1.53
Code:
SD Card Test
------------
File system space is 15466.05 Mbytes.
SD library is able to access the filesystem
Reading SDTEST1.WAV:
Overall speed = 1.63 Mbyte/sec
Worst block time = 0.74 ms
25.33% of audio frame time
Reading SDTEST1.WAV & SDTEST2.WAV:
Overall speed = 1.48 Mbyte/sec
Worst block time = 1.35 ms
46.67% of audio frame time
Reading SDTEST1.WAV & SDTEST2.WAV staggered:
Overall speed = 1.48 Mbyte/sec
Worst block time = 1.00 ms
34.33% of audio frame time
Reading SDTEST1.WAV, SDTEST2.WAV, SDTEST3.WAV:
Overall speed = 1.46 Mbyte/sec
Worst block time = 1.97 ms
68.04% of audio frame time
Reading SDTEST1.WAV, SDTEST2.WAV, SDTEST3.WAV staggered:
Overall speed = 1.46 Mbyte/sec
Worst block time = 1.33 ms
45.84% of audio frame time
Reading SDTEST1.WAV, SDTEST2.WAV, SDTEST3.WAV, SDTEST4.WAV:
Overall speed = 1.46 Mbyte/sec
Worst block time = 2.65 ms
91.41% of audio frame time
Reading SDTEST1.WAV, SDTEST2.WAV, SDTEST3.WAV, SDTEST4.WAV staggered:
Overall speed = 1.46 Mbyte/sec
Worst block time = 1.68 ms
57.87% of audio frame time
Teensyduino 1.54 Beta 5
Code:
SD Card Test
------------
SD card is connected :-)
Card type is SDHC
File system space is 15466.05 Mbytes.
SD library is able to access the filesystem
Reading SDTEST1.WAV:
Overall speed = 1.01 Mbyte/sec
Worst block time = 0.99 ms
33.98% of audio frame time
Reading SDTEST1.WAV & SDTEST2.WAV:
Overall speed = 0.89 Mbyte/sec
Worst block time = 2.59 ms
89.27% of audio frame time
Reading SDTEST1.WAV & SDTEST2.WAV staggered:
Overall speed = 0.89 Mbyte/sec
Worst block time = 2.14 ms
73.79% of audio frame time
Reading SDTEST1.WAV, SDTEST2.WAV, SDTEST3.WAV:
Overall speed = 0.89 Mbyte/sec
Worst block time = 3.57 ms
123.01% of audio frame time
Reading SDTEST1.WAV, SDTEST2.WAV, SDTEST3.WAV staggered:
Overall speed = 0.89 Mbyte/sec
Worst block time = 2.74 ms
94.37% of audio frame time
Reading SDTEST1.WAV, SDTEST2.WAV, SDTEST3.WAV, SDTEST4.WAV:
Overall speed = 0.87 Mbyte/sec
Worst block time = 4.84 ms
166.82% of audio frame time
Reading SDTEST1.WAV, SDTEST2.WAV, SDTEST3.WAV, SDTEST4.WAV staggered:
Overall speed = 0.90 Mbyte/sec
Worst block time = 2.97 ms
102.37% of audio frame time