Data accumulation rate

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Revision as of 12:54, 22 June 2013 by Dvw (talk | contribs)

This page gives some rules for estimating the accumulation rate of data on disk for a running MCE.

In general, during a regular acquisition, the data rate of an MCE is:

<math>S_w \times N_c \times N_r \times R</math>

where:

  • <math>S_w</math> is the word size (=32 bits)
  • <math>N_c</math> is the number of columns read (<math>=8 \times N_{RC}</math>, where <math>N_{RC}</math> is the number of readout cards used)
  • <math>N_r</math> is the number of rows read
  • <math>R</math> is the read-out data rate

A useful approximation is:

a single readout card reading 41 rows at 400 Hz is <math>\approx0.5</math> megabytes/second.

Here's are some tables of accumulation rates for a two readout card 48HP subrack (multiply by 2 for a full sized 72HP subrack with 4 readout cards) for various data rates and numbers of rows:

48HP subrack data accumulation rate in Gigabytes (<math>10^9</math> bytes) per hour
100 Hz 150 Hz 200 Hz 300 Hz 400 Hz 600 Hz
25 rows 0.55 0.8 1.1 1.6 2.1 3.2
33 rows 0.7 1.1 1.4 2.1 2.8 4.2
41 rows 0.9 1.3 1.8 2.6 3.5 5.3


48HP subrack data accumulation rate in Gigabytes (<math>10^9</math> bytes) per day
100 Hz 150 Hz 200 Hz 300 Hz 400 Hz 600 Hz
25 rows 12.9 19.3 25.7 38.6 51.5 77.2
33 rows 17.0 25.5 34.0 51.0 68.0 102.0
41 rows 21.1 31.7 42.2 63.3 84.5 126.7