Parallel SCSI data rate of 640 MB/s. Due to the technical constraints of a parallel bus system, SCSI has since evolved into faster serial interfaces, mainly Serial Attached SCSI and Fibre Channel. The iSCSI protocol doesn't even have a physical definition at all but uses any IP network, usually based on Ethernet. , SCSI interfaces had become impossible to find for laptop computers. Adaptec had years before produced PCMCIA parallel SCSI interfaces, but when PCMCIA was superseded by the ExpressCard Adaptec discontinued their PCMCIA line without supporting ExpressCard. Ratoc produced USB and Firewire to parallel SCSI adaptors, but ceased production when the
Thin client farm. The server-side infrastructure uses cloud computing software such as application virtualization, hosted shared desktop (HSD) or desktop virtualization (VDI). This combination forms what is known as a cloud-based system where desktop resources are centralized at one or more data centers. The benefits of centralization are hardware resource optimization, reduced software maintenance, and improved security. Thin client hardware generally support a keyboard, mouse, monitor, jacks for sound peripherals, and open ports for USB devices (e.g., printer, flash drive, webcam). Some thin clients include legacy serial or parallel ports to support older devices such as receipt printers, scales or time clocks.