South Wing Computer Room SRF
Background
The South Wing Computer Room is one of a number of Small Research Facilities (SRFs) within the Department. These were primarily set up as a mechanism for recovering full non-direct costs compared to the 1/7th that we typically receive from the University from grant overheads. In addition, the running costs of an SRF are included in the charges for its use, thus ensuring funding for support staff and the maintenance and replacement costs of its infrastructure equipment. There are 25 racks available for housing research groups' computing equipment.
In the case of the Computer Room, the main cost being recovered is that of the electricity used which might typically be around £4,000 per half rack per annum for a half rack research server farm plus the infrastructure cost of £682 per half rack per annum (see below).
There are two models for charging for use of the SRF: Model A and Model B. In Model A the service provided is rack space with power and network connections in a secure air conditioned environment; the research project is responsible for buying and running the computers. In Model B the SRF also owns and runs the computers, charging on the basis of computer time used.
Contact
- Computing: comp-admin@eng.cam.ac.uk
- Grant proposal details: research-applications@eng.cam.ac.uk
Details
Model A - Serviced Rack Space
Rack space is let out in multiples of half a 42U rack with two components to the charge:
- Infrastructure Cost: £682/half rack/annum
- Electricity Cost: 11.73p/kWh actual metered usage (includes CRC Levy - February 2012)
The charges are levied per half rack as this is the smallest unit which the electricity metering equipment can independently measure. A maximum of 32A (i.e. approx 7.5kW) is available per half rack. From the perspective of the SRF, a half rack may be shared between more than one research project but these must themselves be responsible for splitting the monthly bill between the projects in a way which is fair and acceptable to the auditors of the project.
The infrastructure charge comprises technician and administrator time and the maintenance and replacement of: networking; the racks; power metering and control; and console equipment. This can be expected to increase by roughly the average of the annual wage and price inceases.
The electricity charge is based on the rate currently paid by the University, 9.76p/kWh, multiplied by a factor of approximately 1.1 to include the associated air conditioning cost to dispose of the heat generated. The air conditioning used is a highly efficient water cooled system (a conventional DX air conditioning system would require a factor of around 1.8 times). The Government recently introduced a mandatory CRC Carbon Reduction Commitment (CRC) Levy which the University has decided to charge @ 1p per kWh. This will be included in the Electricity Cost from February 2012.
As an indication: a stack of 10 servers (medium performance 1U PC), each consuming 250W continuously for a year would incur an electricity charge of around £2,568 (10x0.25x24x365x0.1173) plus the infrastructure charge for half a rack £682 giving a total of £3,250/annum. But note that this is just an indication, different types of computer will consume very different amounts of power and it is important to estimate on the basis of the actual equipment proposed and not rely on this figure for budgetary purposes. There will frequently also be a trade-off between purchase price and running costs, with cheaper CPUs consuming more power.
Model B - Payment for use of Computer Time
This is less well developed than Model A but on top of the Model A costs includes Computer Officer time, extra administrative costs and the cost of the computers written off over three years. Various variants of this scheme are possible including ones in which the SRF in effect administers the sharing of a server farm amongst a number of Research Groups.