Borut blessed the following as a correct and accurate summary of the current statements from various CEB and ICB discussions, representing the ATLAS position on new hardware.
The VO card represents a bare minimum for ATLAS usage, and is set so that we can make maximum use of existing (and often aging resource). However, many ATLAS tasks require more than the minimum on the VO card. Indeed, reconstruction, which
is an increasing feature on Tier 2s as well as Tier 1s and Tier 0, currently requires 3GB/job slot, even using AthenaMP. While we are working on keeping the memory and other resource usage down, the increasing pile-up makes increases likely in all activities.
Accordingly, ATLAS would wish new purchases to have at least 3GB/job slot.
While there are various changes underway on the computing model, including data federation, the best estimate for the disk to CPU balance at a Tier 2 remains essentially unchanged.
ATLAS Tier 2s should have ~10GB connectivity. This requirement is likely to rise over run 2.
Best
Roger
