GNU Radio, One Step at a Time: [Discuss-gnuradio] Expensive file write operation

Hi,

I am trying to capture RF data thru X310 from 2 channels and writing them to file using GNU Radio. But when I use a sampling rate of 20 MHz, packets start dropping badly.

I have a very decent Laptop i7 8th Gen, SSD, 16 gb RAM. I also observed the CPU performance, it does not look stressed at all. I mean, none of the cores were reaching anywhere near to even 50%.

Am I doing something wrong? For 10MHz sampling rate it is good, no overruns.

I have attached my flowgraph, and the cpu performance screenshot.