US Patent 7447920 Workload placement based on thermal considerations

A method of workload placement among servers includes receipt of a workload request. The method also includes selection of a group of servers from a set of servers capable of performing the requested workload. In addition, server workload indexes, which are ratios of temperature rises due to re-circulation load for the servers in the group of servers to temperature rises due to re-circulation load for the set of servers, of the servers in the group of servers are calculated. Moreover, the workload is placed on one or more of the servers in the group of servers based upon the server workload indexes of the servers in the group of servers.