Two IDE Hard Drives on the same Ribbon Cable

[JonB]

I am not having any obvious problems with this vendor provided Matrox RTX.100 based video system, but wonder if it is "optimum"

The vendor provided INTEL 865PERL Motherboard has a boot drive on IDE0 Master, a DVD Burner on IDE0 Slave, and then two identical 250GB drives on IDE1.

In WinXP, the two drives are Striped together as a 500GB drive for video purposes. The motherboard does not have RAID capability, and I don't have a card to drop in.

My question (finally) is - would the RAID performance be better if both 250GB drives were on different ribbon cables?

If so, how would WinXP react to me moving the cables around? Would I lose my Volume and all the data? If the volume didn't mount properly with the cables changed, could I put it back the way it was without ANY risk of data loss?

Keep in mind, I'm not having problems, just concerned that performance could be better.
Thanks. JonB

 

[FlyingPenguin]

My question (finally) is - would the RAID performance be better if both 250GB drives were on different ribbon cables?

Most RAID chipsets require that both drives in a 2 drive RAID array be on the same ribbon (Promise controllers require this for instance). I'd check your documentation.

If so, how would WinXP react to me moving the cables around? Would I lose my Volume and all the data? If the volume didn't mount properly with the cables changed, could I put it back the way it was without ANY risk of data loss?

Windows wouldn't care. The RAID array is managed at the BIOS level. Windows sees it as just one driver in your device manager.

Assuming it was okay to do what you ask, you'd have to boot into the RAID manager's BIOS settings menu and reconfigure the array. WARNING: This would be VERY risky since I have no idea if your RAID controller will properly reconstruct an array if you change a drive address (which is what wil happen if you mov a drive to another ribbon). Again I urge you to check the documentation, and backup your data first.

 

[JonB]

FP, I don't have a RAID card or onboard chip. No BIOS of any kind involved.

This RAID 0 setup is totally software controlled by XP Pro in the Computer Manager.

My question is based on my recollection that the IDE controller cannot actually send or recieve data from both drives on the same cable but has to alternate between them. That could be "out of date" information. But, if it is true, I'm thinking that my RAID could be faster if the IDE controller was talking to two different cables (each half of the RAID 0 drive volume) during a read or write activity.

 

[boomerang]

Two cables is the way to go for sure.

I think you can do what you want in XP after moving one drive but am by no means certain. Don't have at it on my say so unless you have a means of backup prior.

Edit: Here is a KB article that pertains to 2000. It may raise more questions than it answers. At least it did for me.

 

[FlyingPenguin]

First of all, any benefits of RAID 0 are being almost totally lost by using software RAID 0. You should be using a hardware solution.

Yes, you probably would benefit from using two different IDE channels in a software solution, although again I would recommend a hardware RAID controller instead. Software RAID 0 isn't even officially supported by Microsoft.

Whether you can easily change one drive now I don't know. 2K/XP uses hardware addressing for the drives. When you move that drive to the other ribbon it will be at a different hardware address and Windows won't detect it - you'll "break" the array and I don't think there's any way of restoring it.

 

[JonB]

The reason for Software RAID is that this video editing system uses the Matrox RTX.100 real time card. It is very sensitive to PCI bus activity (too dasm sensitive). Matrox warns against using PCI Raid cards for that reason. As a video editing system, it may ultimately be better for me to break the RAID entirely and use each drive standalone, one as a capture drive, the other as a output drive. ATA 7200rpm drives with big buffers are well above the minimum spec for capturing DV-AVI files.

the KB article reference by Boomerang discusses the way that XP stores volume information on each disk of the volume so that it can "reassemble" itself. Sounds promising but I'm not in a risk-taking mood on this job. Thanks.

 

[RZaakir]

Any 64-bit drivers for that RTX.100 yet? That's the only thing keeping me from usinf XP-64.

 

[LiLithTecH]

The 865PERL does support SATA RAID.

 

[lansalot]

First of all, any benefits of RAID 0 are being almost totally lost by using software RAID 0. You should be using a hardware solution.

Not true. There's a big downer on software RAID mostly by people presuming far too much about it. If you are asking for IO, then your CPU can likely afford the overhead as it sits waiting for that data. The main exception to this is parity calculation, but that's of no consequence in a stripe.

Whether you can easily change one drive now I don't know. 2K/XP uses hardware addressing for the drives. When you move that drive to the other ribbon it will be at a different hardware address and Windows won't detect it - you'll "break" the array and I don't think there's any way of restoring it.

It's software raid which means dynamic disks. You can take the two disks out and stick them in another XP machine (if you like) and that system will recognise the striped volume. You won't break the array at all just by moving it to another location, that's just ridiculous.