Need to make sure your using a mirco SD card with a high rate of read speed. Get a sandisk extreme or extreme plus 64G. I had allot of issues with same deal on my go pros, they are like $30 on amazon.
Read speed is important, but I'm thinking he means high rate of WRITE speed since that's what your doing when recording.
Sandisk Extreme Pro 95MBs/read , 90MBs/write
Sandisk Extreme Plus 95MBs/read , 90MBs/write
Samsung PRO+ 95MBs/read , 90MBs/write
Every now and then BestBuy will put the Samsung's on sale, online or store.