Before the dot-com bubble broke, capacity-on-demand schemes meant one thing: the ability to quickly and painlessly turn the volume up. Hewlett-Packard is one of many companies that now knows all too well that what goes up often has to come down. So HP is introducing a model rather artlessly known as Temporary Instant Capacity on Demand, or TICoD, for buyers of its Superdome servers.

The new model lets customers buy servers with some dormant CPUs that can be activated when they buy electronic keys. Not much new there, but the $3,400 keys activate the CPUs for 30 days. If server demand falls, customers can either call HP to have the CPUs shut down or they can simply not renew the activation keys.