Data transfer block size

[asukumari]

Data transfer block size (multiple of 512 bytes based on your disk sector size) can be controlled to acquire total number of samples larger than scope's on-board memory limitations. This example derived from here implements a classic producer-consumer method for high-stream data stream.

In my case with the highest sampling rate of 1.25GS/sec/Ch I am only able total samples of 4.194M (4194303). In other words

total acquisition time  = record_length / sampling_rate = 4.194M/1.25G ~= 3.35ms

If I want to acquire for a longer duration (say 2 times = 6.7ms). The record_length should be 8.388M (2 times of 4.194M). Changing or lowering the block size didn't seem to help anything.

1. How does the data transfer block size really affect the size and speed of data acquired?
2. How can I acquire more samples at the same sampling rate but for a longer duration by controlling the block size?

Attached contains all required files to run niScope Stream to Disk Queues Win32 File IO-a02.vi which is configured to write to a TDMS file instead of a binary file.