Writing/Reading Speed issues (c#)

[Rob777]

Hello everyone!
I had serious problems with speed of writing and reading in c#. Ive done tests (look at NI.jpg) and speed of writing is about 2 sec, and reading about 7-8 sec. 

Its a disaster for my project. This is a peice of my code of reading:

double[] PV=firstchannelsInterpol[0].GetData<double>();
double[] SP = firstchannelsInterpol[1].GetData<double>();
double[] OP = firstchannelsInterpol[2].GetData<double>();
double[] OPmin = firstchannelsInterpol[3].GetData<double>();
double[] OPmax = firstchannelsInterpol[4].GetData<double>();
double[] PVmin = firstchannelsInterpol[5].GetData<double>();
double[] PVmax = firstchannelsInterpol[6].GetData<double>();
Int32[] Mode = firstchannelsInterpol[7].GetData<Int32>();
string[] Time = firstchannelsInterpol[8].GetData<string>();

Am I doing smth wrong?
Thanks

[rizardus]

How did you configure your task and the sampleclock? I had a similar problem when i read at high frequencys. I could fix it for me with changing the setup of the sampleclock.

_mainTask.Timing.SampleTimingType = SampleTimingType.SampleClock; // To slow. 

_mainTask.Timing.SampleTimingType = SampleTimingType.PipelinedSampleClock; // Fast, no problems.

Also, what device are you using?

[Rob777]

In real project I receive data from OPC. But now  generate it. Im using this article https://www.ni.com/en/support/documentation/supplemental/06/introduction-to-labview-tdm-streaming-vi... and there is nothing about sampleclock and task. 
I will really appreciate if you give me some examples or well written articles

[rizardus]

When you generating the data yourself then its strange that you get a timing issues. Maybe this can help you. It is also described in detail in the Measurement Studio help.

Learn 10 Functions in NI-DAQmx and Handle 80 Percent of Your Data Acquisition Applications

[Rob777]

Thanks, I will read it. But what do you think about the article I gave. Is it not modern?

[rizardus]

I used the same for my TDMS Streaming helper class but its more about streaming data to a file and not reading from a device.

measuredData = channels[0].GetData<double>();

Is used to read data from an aleady opened TDMS file.

[Rob777]

Im creating a database based on tdms. So I have to read from an opened tdms file.

[rizardus · Accepted solution]

In this case if you really want faster read times you can defragment your TDMS file before reading or consider using a faster harddrive like a Solid State Disk. The bottleneck is probably your Drive/IOPS. As far as i know there is not much that you can do software wise to speed up the read and write operations except defragmenting the TDMS files.

[Rob777]

My academic supervisor made similar tasks by LabView and speed is very high about 200 ms. Maybe problem in measurement studio's functions, i dont know

[Rob777]

Defragmentation really helped me. Thank you!