For a number of months there's been an effort to replace the CFQ I/O scheduler with BFQ inside the Linux kernel. That isn't happening for the current Linux 4.8 cycle, but new patches were published today in pursuing this goal.
Group-buy site launches 40Msps BeagleBone ADC cape
The Raspberry Pi was given consideration, but Google Research chose the BeagleBone on the strength of its PRUs, which can access all 512MB of the BeagleBone’s system RAM. “This lets us dedicate the PRUs to the time-sensitive and repetitive task of reading each sample out of an external ADC, while the main CPU lets us use the data with the GNU/Linux tools we’re used to,” says Google Research.