# Buffer size constraints

**URL:** <https://forum.quantasylum.com/t/buffer-size-constraints/1642>\
**Category:** QA40x\
**Created:** [December 7, 2024, 11:45pm UTC](https://forum.quantasylum.com/t/buffer-size-constraints/1642 "2024-12-07T23:45:32Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Elmar](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@Elmar](https://forum.quantasylum.com/u/Elmar)\
**Post date:** [December 7, 2024, 11:45pm UTC](https://forum.quantasylum.com/t/buffer-size-constraints/1642/1 "2024-12-07T23:45:32Z")

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Hi,

For my measurements I would like to use larger measurement buffers than the software allows at this moment. I have quite some lag in my system, and I would like to compare the immediate response being sent out (=without lag) with the DUT’s response in -preferably- one go.

For me it would be ideal to use a measurement buffer that allows for ~20 seconds of recording at 192 ksps. This is really large compared to the current maximum buffer. I would not use that big FFT`s, but I would need a buffer of 2^22 samples (maximum now is 2^18 samples).

Would this be possible to add? I would really appreciate this if it is anyhow possible!

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**Author:** ![matt](https://avatars.discourse-cdn.com/v4/letter/m/a6a055/32.png) [@matt](https://forum.quantasylum.com/u/matt)\
**Post date:** [December 9, 2024, 8:07pm UTC](https://forum.quantasylum.com/t/buffer-size-constraints/1642/2 "2024-12-09T20:07:51Z")

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Hi @Elmar, the current software will have trouble with buffer sizes this size in that certain operations (cursors and 1/n octave filtering). There is software being worked on the background (no date known) that will easily cope with large data sizes. I know that doesn’t help you right now, but I just wanted to acknowledge the issue.

> I would not use that big FFT`s,

Is your issue that you have a huge delay, and you just need to test tones with a 20 second delay? If that is the case, there’s a setting called Latency Compensation that can compensate for system delays. Current it maxes out at 2.73 seconds, but I think that could be increased without issue.

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**Author:** ![Elmar](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@Elmar](https://forum.quantasylum.com/u/Elmar)\
**Post date:** [December 9, 2024, 8:53pm UTC](https://forum.quantasylum.com/t/buffer-size-constraints/1642/3 "2024-12-09T20:53:25Z")

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Actually I’m working on a frequency transforming system, which records in realtime and plays back slower. The problem is that I would a high samplerate stimulus, which is slowed down significantly and then played back. (where I could loose the samplerate, but would need the bufferlength).

I would handle the buffer only via an API call but I do understand you might not be able to put it in the main SW branch ☹ .