EF Organisation & Costing. Notes for the meeting on 2 Apr 2003

											GMO
										     02-04-03


 - Chris, Saul, Bob, Giuseppe


 - Sizing the EF sub-systems:

	- number of SFIs
	- number of SFOs
	- number of EFPU (1 EFPU = 1 dual-cpu box as for level-2)

	- HZ/CPU = 1 --> 2HZ of EB rate per EFPU box
	- at 3.3 KHz -> ~ 1600 EFPUs

 - Organisation of EF in terms of sub-farms

	1 sub-farm consists of:

		- N SFIs
		- M SFOs
		- 1 GE switch
		- k EF clusters; each cluster consisting of 1 GE switch and j EFPUs

	if ~ 30-40 HZ EB rate per SFI, number of EFPU/sub-farm ~ (number of SFI * 30-40)/2
	e.g. 20 SFI-> 600-800 HZ per sub-farm -> 300-400 EFPU/sub-farm


	Numerology:

	case 1) 4 sub-farms. Then

		~ 20 SFI
		~ 5 SFO
		~ 50 port GE switch
		~ 18 clusters, 23 EFPU/cluster

	

	case 2) 8 sub-farms

		~ 10 SFI
		~ 2 SFO
		~ 24 ports GE switch
		~ 9 clusters, 23 EFPU/cluster

	etc.

	Costing estimate: see Bob's


 Concerns:

	a) what-if EFPU processing rate is "wrong" y a factor of 2 (upwards)... will have to increase
	   accordingly the number of SFIs?

	b) partitioning and assignement of lvl2 trigger types to specific sub-farms... Understand issue of
	   EF granularity (in terms of number of sub-farms)