You have exactly as much time as at 30fps at 22x higher resolution. You dont need to constantly reuse the same 52KB buffer. Data comes at a steady snail 35MB/s pace. Pee 3 should even be able to save it on USB2 HDD in real time with no compression.
last time I tried USB 2.0 hdd on pee3 did 35MB/s on the dot