Exclusive IT Week tests of VMware's ESX Server partitioning tools show that software running in an ESX virtual machine operates at the same speed as it would in a conventional deployment. This could give the green light to firms contemplating server-consolidation projects using this tool.

The impetus for consolidation was boosted late last week when Microsoft announced in the US that it would alter licensing terms for some of its server software. From April, customers with partitioned servers need pay only according to the processors actually running the software, rather than for every processor in the server. However, its server operating systems are currently excluded from the initiative.

In our tests of ESX server, we ran the Fluent modelling software that is commonly used to benchmark high-end systems. This tests performance of CPUs and memory, but does not place significant loading on servers' disks or networking capabilities.

Server partitioning is a common feature in high-end Unix and mainframe systems. Analysts say that as the power of Intel-based servers increases, many multi-processor servers will soon deliver far more power than is needed by single applications. Consequently, many smaller firms will soon use partitioning software to run several applications on a single server.

Server partitioning tools enable a single server to run several operating systems. High-end tools such as ESX Server can significantly raise average CPU utilisation, providing a better return on investment.

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