[grizzly]

Let's take my Adaptec 2940U2W host adapter which I have in my primary workstation as an example. This is an Ultra2 SCSI device, which gives me a maximum transfer rate of 80 Mbyte/second. One neat aspect of this host adapter, is that it uses a technology Adaptec calls "SpeedFlex.". Internally, there are three connectors. One for Ultra2 SCSI (80Mb/s), one for Wide Ultra SCSI (40Mb/s) and one for Ultra SCSI (20Mb/s). Externally, you have two connectors. One 68-pin for Ultra2 SCSI and one 50-pin for Ultra SCSI. Therefore, you get the maximum throughput no matter what kind of device is connect to the host adapter. In addition, one aspect of the SpeedFlex technology is that it can operate the different buses at the different speeds simultaneously, so there no performance lost on one bus because of a slow device on another bus.

The "W" at the end of the host adapter name means that it has the Wide Ultra SCSI connector. Adaptec also produces the 2940U2, which has the same specifications, but without the internal Wide Ultra SCSI connector and without the external Ultra2 connector. Note that in each case, devices supporting older SCSI standards can still be connected.
Das da oben gerade auf einem Linux Tutorial gefunden.