VMware launched its next generation hypervisor, ESX Server 4.0, and the related tools for managing it, called “vSphere” rather than Virtual Infrastructure. The vSphere stack embodies a strategy and product set that VMware used to call the Virtual Data Center Operating System, or VDC-OS. Now, says Bogomil Balkansky, vice president of marketing at VMware, it goes by the name Cloud OS. With ESX Server 4.0, VMware is boosting the CPU count in a single VM to eight (that’s eight cores with HyperThreading off and four cores with HyperThreading on), and each VM can have up to 255 GB of memory allocated to it (not 256 GB, but 255 GB, according to Balkansky.) Network bandwidth has risen by more than a factor of four to 40 Gb/sec, and a single hypervisor can cope with more than 200,000 IOPS of disk bandwidth.