Can I use a single drive with a Raid card?

succubiss · Post by **succubiss** » Tue May 14, 2002 1:19 pm

I just got an ata100 drive, and I was looking for an ata100 controller card for my BH6.

I found an new ata100 raid card for much cheaper at compgeeks ($18+shipping) than vanilla ata100 cards go for.

I was wondering if I could use a single drive on this card and get the ata100 performance gain, while keeping the raid card for a future second drive.

Post by **FlyingPenguin** » Tue May 14, 2002 3:54 pm

Sure, should be no problem.

By default most RAID cards I've used (IWill & Promise) will default to two seperate drives, then you need to go into the RAID BIOS to setup your array.

chottoED · Post by **chottoED** » Wed May 15, 2002 2:22 pm

i believe promise chipsets allow for single drive raid arrarys whereas highpoint ones don't (at least when i was using them)

succubiss · Post by **succubiss** » Wed May 15, 2002 5:01 pm

good deal. i went with it. Thanks for the pointers guys.

this one uses an Si---- something chipset, haven't heard of it before, but it should be fine.

thanks again

Busby · Post by **Busby** » Wed May 15, 2002 5:35 pm

chottoED: no such thing as a single drive array. Minimum RAID level (RAID0) requires 2 drives. The card will function as a regular IDE controller though.

chottoED · Post by **chottoED** » Thu May 16, 2002 1:04 am

Bubsy have you ever used a Promise RAID card before?

EvilHorace · Post by **EvilHorace** » Thu May 16, 2002 6:36 am

It's been my previous understanding that the idea of a functional RAID array requires two identical IDE HDDs. Has something changed that? Are we talking about something else here?

Busby · Post by **Busby** » Thu May 16, 2002 6:43 am

chotto: No but why would Promise have a special RAID level that other controllers won't? Why would Promise break the industry standard on what RAID is? Isn't a single drive array just a plain ole drive running off of an IDE controller? What benefits would you get for running a single drive array? Nothing.

Post by **FlyingPenguin** » Thu May 16, 2002 9:15 am

A RAID array requires two drives. It's not an array and it's impossible to get any benefits of an array with one drive.

Most controllers DO NOT require you have two IDENTICAL drives. The Promise for sure doesn't. I have a client who sent one of his 30 Gb drives back for RMA and got a 40Gb in return. No problem restoring his RAID mirror, just that the array is not utilizing 10Gb on one of the drives.

RAID striping is the same. I have an IWill (Highpoint) controller with two different brand 30Gb drives - MAxtor & WDC - one drive is slightly larger than the other. No problem.

As far as I know most RAID controllers will work as a standard ATA (non-RAID) controller if there's no RAID configuration defined in the contoller's BIOS menu.

chottoED · Post by **chottoED** » Thu May 16, 2002 9:36 am

guys... stop throwing dictionary definititions at me...
i know raid requires 2 or more...
however, as i said, promise chipsets have a slightly different function... i allows you to configure a raid array via the promise bios use only one drive...

and i've benched it to confirm, there is a performance difference between running the drive as regular formatting and the single raid drive array

so... try out something with a promise chipset and get back to me

Busby · Post by **Busby** » Thu May 16, 2002 9:48 am

I don't see how you have an array with a single drive plus it defies what RAID is.

Also nothing of that is mentioned in a Promise RAID controller's manual or white paper...

chottoED · Post by **chottoED** » Thu May 16, 2002 9:59 am

would you just try it on a Fasttrak before you go on saying I'm wrong?

Busby · Post by **Busby** » Thu May 16, 2002 11:19 am

Upon searching at deja.com the Promise will create a single drive striped array but yet it doesn't act like RAID, it's like using a normal drive. I still can't see how you can classify it as a RAID array because the minimum RAID level requires 2 drives. But that's my opinion and you can't really change my opinion.

Post by **FlyingPenguin** » Thu May 16, 2002 1:12 pm

It can't be an "Array" nor can it be all that much faster.

The whole concept behind a striped array is that every other sector is on a different drive, so that statistically your system is going to wait MUCH less time for the next sector to be accessed (pull a sector from drive #1 then instead of waiting for the drive to possibly complete another revolution, fetch the next sector from drive #2, and then go back to #1 etc.).

Only thing they MIGHT possibly be doing is changing the way that the sectors are recorded on the platters of a single drive (normally they're recorded one after another) which leads to some statistical improvement in performance, but it can't possibly be all that much of an improvement.

And it's it's a Mirror array, it would be pretty pointless to have both mirrors on the same drive. The purpose of a mirror is redundancy in case of a drive failure.

chottoED · Post by **chottoED** » Thu May 16, 2002 2:16 pm

There was a 10-15% boost by creating a promise single drive "array". I never said it was a true to dictionary definition RAID array... I just said that they had that capability.
Like I said, this is proprietary to the Promise ATA RAID cards...

It's really quite useless debating this with you when non of you have even tried this.
So let's just drop it... I'm telling you that there's this function, and then you guys keep saying it can't be this or that or it doesn't exist without even trying it out.