# Presentation: 677438

## Data AcquisitionMark Bowden, Margaret Votava

## Parameters

- 250,000 channels
- 4 Bytes/chan
- 2 MHz sample rate
-     			Front-end data rate = 2 TBytes/sec

## Front-end (ICARUS)

- Caen V789 (Digital Board) + V791 (32 channel A/D Board)

- Rack   18 X 32 channels

## FLARE Front-end Assumptions

-  Newer components allow greater packaging density
- 128 or 256 channels (if new amplifier/shaper ASIC)
- Digital board can be reduced to single FPGA and
- 	combined with Analog board
- FE Board count drops from 16,000 to 2,000
-  Eliminate VME
- VME is expensive and provides no added value
- Direct Ethernet connections to FE boards
- 6U Eurocard or 1U (pizza box) packaging

## FLARE Front-end

- 40 X 128 channels (6U packaging)

- 20 X 256 channels (1U packaging)

- 48V Power

## Data Rates

- 1 MByte/sec
- 2 GByte/sec

- 1 KByte/sec
- 2 MByte/sec

- 1 MByte/sec
- 2 GByte/sec

- 1 GByte/sec
- 2 TByte/sec

- Without FE Data Compression

- With FE Data Compression

- Spill Only*

- Continuous

-     * 2 msec per 2 sec cycle
-   ** assuming 128 channels/FEB

- - per FEB**
- - system total

- Note: BTeV is 0.5 TByte/sec

- Data Network

- ...

- FE switches (100)	$15K
- GBE switches (50)	$25K
- _Cables__	__	__	__$10K_
- Total			$50K

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- 5 GByte/sec

## Switch-based DAQ

-  Any size/bandwidth system can be built from low cost
-   switch components.
-  Cost scales as NlogN.
-  Up to 100m (copper) between switches.

- Processing & Data Storage

- 1U dual processor	$2K

- DVD writer		$7K

- (Delay purchase of computers to maximize performance/cost.)

- “Event” Processing

-  An “Event” is an arbitrary time slice of data from all channels
-     2 msec			    4 MBytes
-   20 msec			  40 MBytes
- 200 msec			400 MBytes
-      2 sec			    4 GBytes
-  Choose largest time slice that fits in processor memory
-  For this application, ~100 msec

- “Event” Processing

- Front-end (2000 data sources)

- Ethernet Network

- Processors

- 1

- 2

- 2000

- 1

- 2

- 200

- Source       1
- Source       2
- Source       3

- 1

- 2

- 3

- 200

- 1

- 2

- 3

- 200

- 1

- 2

- 3

- 200

- 1

- 2

- 3

- 1

- 2

- 3

- 1

- 2

- 3

- Destination

- “Event” Processing

- Front-end

- Ethernet Network

- Processors

- 1

- 2

- 2000

- 1

- 2

- 200

- Data transfer time  =  ~40 MBytes/sec * time_slice	[4 sec]
- Processing time  =  Nprocessors * time_slice		[20 sec]

## Data Storage

- Tape
- $300K/PByte

- Hard Disk
- $800K/PByte

- Blu Ray
- $900K/PByte
- <$100K/PByte

- DVD-R
- $100K/PByte
- DVD-RW
- $300K/PByte

## Data Storage

-  continuous readout, without online tracking
- 	- 2 GBytes/sec X 107 sec = 20 PBytes/yr
-  	- $2-6M/yr media cost
-  continuous readout, with online tracking
- 	- 2 MBytes/sec X 107 sec = 20 TBytes/yr
- 	- $10K/yr media cost
- Note:  BTeV includes 2 PBytes of hard disk (@ $600K/PByte) in base
- DAQ construction cost.  Offline storage is part of operating cost.

## DAQ Costs

- Ethernet Network
- (~$50K)

- Processing Farm
- (~$500K)

- Data Storage
- (~$50K @ 2MB/sec,
- ~$1M @ 2GB/sec
- + media cost)

- Note: DAQ based on all commercial hardware

## DAQ Costs

- Slow Controls		~$200K
- Timing System		~$50K
- Development System	~$100K
- Infrastructure		~$50K

## DAQ Cost Summary

- 	DAQ hardware			~$1.0M
- 	DAQ software			~$2.0M
- 	DAQ management		~$0.5M
- 	DAQ operating cost		~$100K/yr
-  without online tracking
- 	(fewer online processors, but more data recorders)
- 	DAQ hardware			~$1.7M
- 	DAQ software			~$1.5M
- 	DAQ management		~$0.5M
- 	DAQ operating cost		~$4M/yr

## Conclusions

- (“necessary” for continuous readout)
-  online tracking will significantly reduce operating cost by
-    reducing storage media expense
-  DAQ base cost estimate is ~$3.5M
-  DAQ contingency and overhead  estimate is ~$1M