Raid and ATA

[mgculver]

Can anyone explain the relationship (if any) between RAID 0 and ATA 100. Having a discussion at work concerning whether or not drives configured for RAID 0 on motherboards that support raid, were actually running in UDMA 5 mode or not, under Windows 2000 and XP.

Most of these boards and add-on cards configure raid as a pseudo SCSI device?? and as such, ATA would not in the equation??

Thanks,

MC

 

[Nothinman]

There is no relationship between RAID 0 and ATA, they're totally seperate things. If the drives and controller are ATA/100 and you have appropriate cables then yes they'll run in UDMA 5, RAID 0 or not.

 

[Nothinman]

Whoops, double post.

 

[Buddha Bart]

The "motherboards that support raid" actually just have a pci raid controller card grafted onto the motherboard. As long as that 'card' supports ATA 100 then yes, the drives will work at ata100 regardless of if they are in a raid array or not.

bart

 

[Nothinman]

Actually most of the IDE RAID controllers aren't really RAID controllers, they're just IDE controllers with some 'magic' firmware to make it bootable, the RAID portion is done in the drivers in software.

 

[EarthedCT]

<< Actually most of the IDE RAID controllers aren't really RAID controllers, they're just IDE controllers with some 'magic' firmware to make it bootable, the RAID portion is done in the drivers in software. >>



I'd just assumed that the RAID BIOS did most of the work (in regard to the 'structure' of the array)... But then, I don't know much more than mgculver about RAID

 

[Nothinman]

I'd just assumed that the RAID BIOS did most of the work (in regard to the 'structure' of the array)... But then, I don't know much more than mgculver about RAID

Some do, but they're the ones that cost only slightly less than a SCSI RAID card, the IDE ones are so cheap beause they're essentially not real RAID.

 

[Devistater]

<< Can anyone explain the relationship (if any) between RAID 0 and ATA 100. Having a discussion at work concerning whether or not drives configured for RAID 0 on motherboards that support raid, were actually running in UDMA 5 mode or not, under Windows 2000 and XP.

Most of these boards and add-on cards configure raid as a pseudo SCSI device?? and as such, ATA would not in the equation?? >>



More thoughts, the pseudo scsi thing is only for purposes of "fooling" windows so it won't have a problem using it.
The RAID should automatically run at the highest speed that both the card and drives support. For instance in my KT7A RAID mobo, I can go into the raid setup and specify differant levels of UDMA/ATA speed if I wish, I just left it on the highest (default). BTW, my KT7A mobo raid appears as a scsi device also

Regarding drivers, that's some of the story sure, but my raid 0 drive works in dos, I know, I've booted to dos before. Raid 0 and raid 1 don't take much calculation to run, so its cheap to implement in hardware with some in software. I think what you are really thinking of is RAID 3 and 5 where you need to calculate a ton of stuff for the parity.

Finally, there really is no good way to tell if windows 2k/XP really HAS UDMA mode 5 enabled that I know of anyway. Your card/mobo might enable it, but windows might not and thus be slowing it down. Sometimes the software drivers that come with the card have diags that can tell you. Other than that I don't know.

 

[Nothinman]

Regarding drivers, that's some of the story sure, but my raid 0 drive works in dos, I know, I've booted to dos before. Raid 0 and raid 1 don't take much calculation to run, so its cheap to implement in hardware with some in software. I think what you are really thinking of is RAID 3 and 5 where you need to calculate a ton of stuff for the parity.

No, I'm talking about RAID 0 and 1 controllers. The RAID 3 and 5 ones are normally real controllers and cost a good bit more. I don't have anything concrete to back this up so I'll stop now, if I do find anything I'll post again =)