1. Ingredients
24 x 1Gbit port switch with 2 x 10 Gbit uplinks  KCHF
(blocking factor 1.2)
18 x 10 Gbit port (effective) switch with 6 x 10 Gbit uplink  KCHF
Router with 140 x 10 Gbit ports  KCHF
CPU box  KCHF
( 2 x 6 cores, 48 Gbyte memory, 2 x 500 Gb disks, 1 x 1 Gbit NIC)
+ 1 x 10 Gbit NIC  KCHF
All costs are conservative estimates and have an error-bar of 20%
Reference for the equipment (availability and costs) is the end of 2010

2. Other detector readout
1 Gbit switch
LKr and global
event building
1 Gbit lines = copper
10 Gbit lines = fibre
10 Gbit router
10 Gbit switch
Architecture sketch
Flexibility on what is
at the pit and what is
in the center
Don’t assume 9 KB
jumbo frames !
10 Gbit lines
10 Gbit lines
LKr readout
10 Gbit lines
10 Gbit lines
1 Gbit switch
1 Gbit lines
1 Gbit lines
Other detector readout
Computer
Center
Level 2/3 filter farm
Assume
900 LKr readout channels (38 switches == 76 x 10 Gbit ports)
?450? Other detector channels (19 switches == 38 x 10 Gbit ports)
50 kHz, 100 KB/event  5GB/s event building; 10 s spill  50 GB memory total;
216 cores  4 ms/event max. event building (10 Gbit switch == 6 x 10 Gbit ports)
leaves 20 x 10 Gbit ports for level 2/3 farm , 50 KHz , 5GB/s  110ms/event reco-time
480 cpu nodes == 5760 cores
 11 water-cooled racks + infrastructure
Cost estimate
Network = ~ 1.1 MCHF
Cpu nodes = ~ 1.5 MCHF