Hi,
Looking at the source code there are two minor differences. The buffer size is different. When you use the raw API the buffer size is specified in bytes, whereas when you use the libiio the buffer size is in samples and libiio will do the conversion to bytes based on which channels are enabled. The other difference is that DEC_RATE is 32 once and 24 for the other program. I'm not sure though if either will actually make a difference.
- Lars