Virtual machine hardware Version 7 introduced a new VMware Paravirtual storage adapter (PVSCSI). It is considered a high-performance storage adapter recommended for VMs with high I/O usage. PVSCSI can handle high I/O with higher storage throughput while keeping CPU utilization low.
Note
In ESXi 4, the LSI Logic adapter performs better than PVSCSI for VMs doing less than 2,000 IOPS.
More details are available in the VMware KB 1017652 article at http://kb.vmware.com/kb/1017652.
The following operating systems support PVSCSI:
Windows Server 2003
Windows Server 2008
Windows Server 2008 R2
Windows Server 2012
Windows Server 2012 R2
Windows 8
Red Hat Linux 5
These operating systems don't include drivers for PVSCSI by default and the drivers have to be loaded before the virtual disk is recognized during OS installation.