Difference between revisions of "Data accumulation rate"
From MCEWiki
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− | This page gives some rules for estimating the | + | 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 | + | 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> | :<math>S_w \times N_c \times N_r \times R</math> | ||
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! 400 Hz | ! 400 Hz | ||
+ | ! 600 Hz | ||
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! 25 rows | ! 25 rows | ||
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| 1.6 | | 1.6 | ||
| 2.1 | | 2.1 | ||
+ | | 3.2 | ||
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! 33 rows | ! 33 rows | ||
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| 2.1 | | 2.1 | ||
| 2.8 | | 2.8 | ||
+ | | 4.2 | ||
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! 41 rows | ! 41 rows | ||
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| 2.6 | | 2.6 | ||
| 3.5 | | 3.5 | ||
+ | | 5.3 | ||
|} | |} | ||
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! 300 Hz | ! 300 Hz | ||
! 400 Hz | ! 400 Hz | ||
+ | ! 600 Hz | ||
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! 25 rows | ! 25 rows | ||
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| 38.6 | | 38.6 | ||
| 51.5 | | 51.5 | ||
+ | | 77.2 | ||
|- | |- | ||
! 33 rows | ! 33 rows | ||
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| 51.0 | | 51.0 | ||
| 68.0 | | 68.0 | ||
+ | | 102.0 | ||
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! 41 rows | ! 41 rows | ||
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| 63.3 | | 63.3 | ||
| 84.5 | | 84.5 | ||
+ | | 126.7 | ||
|} | |} |
Revision as of 16:47, 9 October 2012
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:
150 Hz | 200 Hz | 300 Hz | 400 Hz | 600 Hz | |
---|---|---|---|---|---|
25 rows | 0.8 | 1.1 | 1.6 | 2.1 | 3.2 |
33 rows | 1.1 | 1.4 | 2.1 | 2.8 | 4.2 |
41 rows | 1.3 | 1.8 | 2.6 | 3.5 | 5.3 |
150 Hz | 200 Hz | 300 Hz | 400 Hz | 600 Hz | |
---|---|---|---|---|---|
25 rows | 19.3 | 25.7 | 38.6 | 51.5 | 77.2 |
33 rows | 25.5 | 34.0 | 51.0 | 68.0 | 102.0 |
41 rows | 31.7 | 42.2 | 63.3 | 84.5 | 126.7 |