basic scsi question: what's difference between single and dual channel scsi? advantages and disadvantages?

[Soldat]

???

 

[bozo1]

Dual supports more devices.
Many people segregate their LVD drives (Ultra 2, Ultra160) from SE drives (CD-ROMs, tape drives, older SCSI drives) so as not to slow down the LVD bus.

 

[Drakkhen]

Well, I have a 39160 which is a dual channel SCSI card. That means it is basically two controllers in one.

Each channel can handle up to 15 devices. Also, each channel has it's own separate bandwidth. So, you can put all HD's on one channel, all of your slower devices on the other channel (tape drives, CD's, etc.) and they won't interfere with each other (since, with scsi, the chain is usually reduced to the slowest speed of the slowest device on the chain).

Hope that helps a bit.

 

[Soldat]

interesting, thank you

 

[Boonesmi]

most people dont need more then 15 devices... so in that aspect single channel is fine

the main reason i would want dual channel would be for speed

for example if its an u160 controller then you have 160mb of bandwidth... say you have some harddrives that are capable of 50mb/s data transfer then 3 of them on the channel even if all are used at the same time will only be using 150mb of the 160mbs bus... in which case everything is fine

but if you had 10 fast harddrives on the same channel you might run into some bandwidth problems (hehehe not to many home users have to worry about that)