[bjames]

Looking to connect 2 or Medea Video Raid RTS's that use the Ultra 160 VHD68 SE LVD connections.  I know I need to find a PCI cage first.

My question is what Ultra SCSI UW160 cards are compatible.. Adaptect? or do I have to stay with SGI or Qlogic. 

I dont want Differential as I went that road with the XIO Ultra scsi board and cannot get it to see any of my drives - even though port 1 is supposed to be auto sensing and works with SE.

[uunix]

I have a Medea Video Raid unit with VHD and mine is run from the default external SCSI connector and I have a cable that converts the two.

[bjames]

The external UW scsi is supposed to support 40mb/sec and the Medea Raid RTS is supposed to provide 160MB/sec so in order to get full speed (multiple streams of uncompressed SD video), I would need 4 SCSi ports striped across 4 raids.

What kind of video performance are you getting?

[jan-jaap]

The external UW scsi is supposed to support 40mb/sec and the Medea Raid RTS is supposed to provide 160MB/sec so in order to get full speed (multiple streams of uncompressed SD video), I would need 4 SCSi ports striped across 4 raids.

What kind of video performance are you getting?

Beware that the random I/O speed of the disks is a lot less than the streaming speed. So you want to avoid hitting the same disk with multiple streams. A single stream of uncompressed SD video is ~ 25MB/s I believe.

The QLogic QLA12160 is probably what you want, it provides 2 U160 LVD scsi ports. Note that the bottleneck is the XIO-PCI bridge in the PCI 'shoebox' which maxes out somewhere between 160 and 200MB/s. The shoebox is only 64bit/33MHz PCI, the QLogic card exists in a 64bit/33MHz and 64bit/66MHz version. You will only benefit from the latter with an O3K/Fuel/Tezro class system (it will still work in an Octane, of course).

[uunix]

The external UW scsi is supposed to support 40mb/sec and the Medea Raid RTS is supposed to provide 160MB/sec so in order to get full speed (multiple streams of uncompressed SD video), I would need 4 SCSi ports striped across 4 raids.

What kind of video performance are you getting?

Actually yes, it's best not to go the same route as I have, I only use mine for files and not the stoneFS.

[jan-jaap]

but how to create and handle raid-stripping on Irix?

See: IRIX® Admin: Disks and Filesystems

There's XLV and XVM, XLV is older, XVM has more advanced capabilities. For a simple stripe you can use either and the result will be the same. You don't need a license to stripe disks (RAID 0), only to mirror (RAID 1). Other RAID levels are not supported.

[bjames]

The shoebox is only 64bit/33MHz PCI, the QLogic card exists in a 64bit/33MHz and 64bit/66MHz version. You will only benefit from the latter with an O3K/Fuel/Tezro class system (it will still work in an Octane, of course).

This is great information as I have seen both for sale but one being more expensive - now I know.  thanks