SCSI Raid

[Dumass_Freakboy]

Hi hi everbody,

I have a configuration of a dual channel SCSI card in my system now, because I thought I would need different channels for the seperate drives much like in IDE. I have been running on 4 9.1GB scsi disks for the past year, and now i'm going to be upgrading cuz 40gb is not enuff space for applications, games and windows...

I was incorrect in assuming I will need seperate channels for hard drives, however, is there a performance benefit in say putting two SCSI disks on seperate channels and then putting them in a RAID0 configuration, rather than putting them all on one chanel?

Anybody knoe?

Thanks,

Matt

 

[MixManSC]

I don't believe different channels would offer any benefit in SCSI. If anything I might wonder if it might actually be worse perfomance in disk to disk copying operations. Also if the card is just a dual channel SCSI controller and not a RAID controller then you would be looking at software RAID which I would not personally reccomend.

 

[Dumass_Freakboy]

It's a hardware raid too.
Adaptec 39320A-R i beleive..
From what I understand.. theres 320Mbit for each channel.. if i had enough disks on the one channel to saturate that channel, then i should go to the second channel.

 

[drizzt81]

I was incorrect in assuming I will need seperate channels for hard drives, however, is there a performance benefit in say putting two SCSI disks on seperate channels and then putting them in a RAID0 configuration, rather than putting them all on one chanel?

only if the STR of the drives exceeds the channel rate. Example: you have ten15K disks in RAID-0 which can sustain >320MB/s. Using two channels may be a good idea here. Given that you have four disks that are likely rather old (due to size), I would doubt that you will see any benefit. This is providing that all your SCSI drives support the same speed, you should separate the Ultra2 from the Ultra160 drives, for example.

 

[Dan_D]

only if the STR of the drives exceeds the channel rate. Example: you have ten15K disks in RAID-0 which can sustain >320MB/s. Using two channels may be a good idea here. Given that you have four disks that are likely rather old (due to size), I would doubt that you will see any benefit. This is providing that all your SCSI drives support the same speed, you should separate the Ultra2 from the Ultra160 drives, for example.

This makes a lot of sense.