Frequently Asked Questions

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General Questions Questions Related to Specific Gage Products Can't Find an Answer?

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Questions Related to Specific Gage Products

Q. I need to digitize a quadrature (I-Q) input using a fast digitizer at a preferred sample rate of 500 MS/s to 1 GS/s.

I used a CompuScope 82G with C++ SDK and found that I get different data transfer rates when I use single channel mode versus dual channel mode. Is this normal?

A. Yes, it is normal to notice a difference in data transfer rates. The memory subsystem of the CompuScope 82G is optimized for single-channel mode acquisition.

The memory banking used in single-channel mode allows full use of the data bus bandwidth, thereby allowing the maximum transfer rate to host memory.

In dual channel mode, the data bus is idle at least 33% of the time, thereby reducing the transfer rate to host memory by the same amount.

Our benchmarks show that data transfer rate is:

80 MB/s in single channel mode;

50 MB/s in dual channel mode.

Note that this discussion only deals with the data transfer rate from capture memory to host PC memory. At acquisition time, the internal data bus provides 100% bandwidth to data being acquired, thereby guaranteeing that not a single bit of data will be lost .

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