It may be a dumb question but if I have the latest atto scsi boards (these have 2 ports) installed in my  xw8400 & xw8600's, when connecting 2 x videoraids, should I have 2 seperate cables leaving the atto board and going into each videoraid OR should I have 1 cable leaving the atto board going into 1 videoraid and daisy chain it to the second videoraid ?

the manual is not clear

thank you

For a single channel HBA, 2 videoraids can be connected using daisy chain method and putting terminator on the 2nd raid.

Since you're using a dual channel HBA, you can connect them in 2 ways (just like what you're thinking): 1) same as for single channel connection (daisy chain method). 2) by connecting 2 cables from HBA going to each videoraid and placing terminator on each raid. I think this way gives better performance or data transfer as twice as the 1st connection. Just make sure to set the correct SCSI IDs like 0 & 1.

I thought I should ask becase on the drawing in the user manual it just shows the disks daisy chained and there is no mention of using both ports of the hba.

cheers anyway

Here, we use it in either way.