CPT White Paper on Tier-1 Computing Resource Needs

In the summer of 2005, CMS like the other LHC experiments published a Computing Technical Design Report (C-TDR) for the LHCC, which describes the CMS computing models as a distributed system of Tier-0, Tier-1, and Tier-2 regional computing centers, and the CERN analysis facility, the CMS-CAF. The C-TDR contains information on resource needs for the different computing tiers that are derived from a set of input assumptions and desiderata on how to achieve high-throughput and a robust computing environment. At the CERN Computing Resources Review Board meeting in October 2005, the funding agencies agreed on a Memorandum of Understanding (MoU) describing the worldwide collaboration on LHC computing (WLCG). In preparation for this meeting the LCG project had put together information from countries regarding their pledges for computing resources at Tier-1 and Tier-2 centers. These pledges include the amount of CPU power, disk storage, tape storage library space, and network connectivity for each of the LHC experiment for the subsequent five years. In this White Paper we describe the current situation for CMS regarding pledged computing resources.